Want to learn

What interests you?  Will it be to mainly make your photographs look better? 

Manipulate two or more photographs into one more interesting image?

Full on digital art and illustration?

Restoring old family photographs?

Photoshop is a highly complex application, but ironically, has got much easier to use because of its Ai driven features. So, my advice is to learn those aspects that will be of most use to you starting out so you can cement the workflows into your memory.  Slowly add to your box of tricks, and practice, practice, practice.

To get you going you need to understand layers and layer masks.

Then selections, but we can usually just click on Remove Background and get a completely usable mask now.

For a complete beginner, Blue Lighting TV is a good channel.  He assumes you know nothing, and leads you a step at a time, and you'll get some interesting effects that you'll be pleased with.

When Marty starts to irritate with his Janet & John  'A is for Apple' naration style, then step up to The Photoshop Training Channel.  and Photoshop Cafe

Think about having a go at our SFTW threads.  They will drive you into creating.  You'll have ideas about what you want your image to be, and have to work out how to do it.  We all learn heaps from doing those threads over the last few years.

When you get stuck, start a new thread and ask for advice.  Those are our favourite threads and you'll lots of help.

It's difficult to recommend the best approach here. Everyone learns differently. Some learn from books, others prefer video courses. Still others swear by courses and workshops offered by relevant institutes.

For me I can say I've learned a lot by watching tutorials that I found on the web, like Youtube or other sites.

You're also find tutorials on Adobes site Adobe Learn

When you open Photoshop, on the Home screen there is a Learn section with many tutorials, some are hands-on. This is a good way to start.