Need help with the basics

In organizer, *none* of the pictures I batch imported is listed.

Are any photos showing up in the Organizer?  There could be several reasons why you are not seeing your photos in the Organizer, so let's try to figure out what happened.  Since you were importing such a large number of images at one time, it is possible that the bulk import failed.  If you have any images appear in the grid, try using the Sort by: Import Batch.  The images are then sorted in the order in which they were imported and will show the date of the import.

In editor, it took me quite a while to find out how to rotate an image (nothing so simple as a right click menu, sadly),

Yes, it's true there is no right-click option.  But there is a one-click button to rotate.  (And a regular menu option.)

I would appreciate a recommendation on software that would be a touch better than MS photo editor but just as easy.

IMO, the beauty of Elements is that it provides a wide range of editing capabilities from beginner to expert.  I have been using it since version 3 and and still learn new things every day.  You haven't told us exactly what you want to do, either with organizing or editing your photos (other than rotating and cropping them).  The MS Photos app can do that as easily as any other app, but you apparently want more.  I have a number of other photo editing programs on my computer and I can't think of any that is less complex than Elements.  I'm sure if you do a Google search you will find other applications to try.  But if you are not willing to learn some basics, I'm not sure you will be happy with any of them. 

We're happy to help with showing the basics, but you need to tell us more about what you are doing.  Hopefully, the following will help you. 

Photoshop Elements consists of two applications - the Organizer and the Editor.  The Organizer catalogs and presents the photos stored on your computer for viewing in one place.  The Editor is used to edit your photos.  When you click the Elements icon on your desktop, it will open the Welcome Screen which has icons/buttons to open each of the programs.  The Welcome Screen is also useful for finding help; there is a text box at the top where you can type in things such as crop a photo.

It is not clear from your post whether you are in the Organizer or the Editor (or the Welcome Screen).

In the Organizer, you should have a grid showing all the photos you have imported.  It should look like one of the following:

I prefer to work in the Details view (which is on the right).  You can toggle between the two views by pressing Ctrl+D.

There are some limited editing options that are available in the Organizer.  You get to these by selecting a photo or photos in the grid and clicking on the Instant Fix button in the toolbar at the bottom of the screen.

This will open a new dialog window where you can make several adjustments to your photo, including cropping it.

Alternatively, if you want more editing options and control, you need to open the file in the Editor.  There are several ways to do this.  I prefer to select an image or images in the Organizer and use the shortcut (Ctrl+I) to open the files in the Editor.

If you are already in the Editor, there are 3 different modes to use:  Quick, Guided and Expert. 

The default usually opens in Quick Mode which has a limited number of tools, but does include the Crop tool.  Obviously, the Expert mode also has the crop tool.

Hope this information moves you along the learning curve. 

@Edison157F said:

Any way to set the defaults so that Elements always saves files in jpeg and to the right folder?

The Save As commands should be sticky.  In other words, the dialog will use the same options as were used the last time you saved a file.  The default is to save an edited file in its original folder location. 

The exception would be if you have added layers to a jpeg file.  Since jpeg does not save layers, the Save As dialog will default to .psd file format.  If you change the file type to jpeg, the file will automatically be flattened. 

Once you get to the jpeg save options dialog, the save quality should also be sticky.  So, it should just be one click to save the jpeg file.

Is this not the save workflow you are experiencing?

@Edison157F 

I do not want to keep buying Elements, or have my heirs do so, to be able to access my photos. I want to keep my photos in a non-proprietorial format, in my folder structure, and on OneDrive (not Adobe; I do not want another subscription storage service).

This is an important question for all of us, and I may add that it's also true with sharing now and not only for your heirs in many years.

As you can see from Greg's excellent answer, you can do anything you want with the Organizer (and from most other external softwares). In short, what your heirs or friends will miss are your personal organization and the powerful management tools based on a catalog.

As you have seen the first thing to consider is to create a file trees structure which can be understood by other readers. Very limited compared to the power of a database. Like other assets management tools, Elements does rely mainly on a catalog and lets you (even helps you) shape your folder tree as you want. For instance it's enough to store your pictures in OneDrive and organize the special 'OneDrive' folder on your computer to share and sync with the Cloud.

The second factor is the ability to keep the tags and captions  available for future readers. The organizer stores those in the catalog for extremely fast searches. Like in many external tools, you have the option to 'write metadata to tags', in the files themselves. The tags will be available when future readers will manage your library with most external organization tools. But this is not automatic, you'll have to do that yourself, which is fast and easy. That makes tags, captions, notes or ratings available, but not albums, creations, stacks or version sets which are only kept in the catalog.

For people who will only have the Explorer or Finder, it's doubtful they can take advantage of the tags and captions available to them.

The Organizer is only a database program.  It does not make copies of the files stored on your computer.  It only keeps a catalog of them so that when you are looking for an image or video, you can find it easily using various tools that are available.  What happens is that the files in your current folder structure are "imported" into the catalog.  This can be done in bulk. So the program will search your computer for the 30,000 image files and will import them into your catalog.  Thumbnails of each file are then available for viewing in various ways such as by folder or in date order.  If you see a file that you want to edit, you can easily send the file to the Photoshop Editor for that purpose.  You can then overwrite the original file or you can save a copy of the file, either in the same folder, or in another one if you want. Presumably,  you save your files in a One Drive synched folder so that your edited file will then be saved to your One Drive Cloud account for backup.

Once your files are in the Organizer's catalog, the program conducts some media analysis and will create smart tags which will help it identify image objects that can be searched for.  You can also create keyword tags and other system tags e.g. People tags which identify faces that have been recognized in an image automatically. The tags can then be saved in a file's metadata and will generally be available for viewing in some form by others who do not have Elements now or in the future.

I hope I have answered your concerns, but feel free to ask for further clarification.

Your files can be stored wherever you want them to be stored on your hard drive.  When you want to save a file, use the File>Save As dialog.  If you have already set the preference option to save to Cloud, there should be a button available to store on your computer. 

Files saved to the Adobe Cloud are saved with a .psdc extension.  However, there is a dropdown menu in the Save As dialog which allows you to switch to jpeg or many other formats: