How to open pdf, jpeg, bmp on iPad?

Because there’s no right-click (because there’s no right button to click), iPad OS in general (not just Photoshop) uses several other gesture-based touch techniques that you may want to research.

The one that’s probably the most similar to right-click is the long press. If you are in the Files app, and you opened any folder (including Creative Cloud Files), long-press a file and when the context menu pops up, tap Share. The Share menu that appears will show a horizontal list of app icons at the top; tap the Photoshop icon. If Photoshop for iPad supports the format, Photoshop will open the file you long-pressed.

Another technique is drag and drop. You can drag an image icon from a folder in the Files app, and then, without releasing that finger (so you don’t drop the file), use a different finger to navigate to the Photoshop app icon on the Home screen or Dock, and then with the original finger that’s still holding the file, position the file over the Photoshop app icon and hold it on the icon until the Photoshop application window pops open, then drop the file into that. Yes, that’s right…one finger can drag and hold the file while another finger navigates, iPad OS does recognize the two separate and simultaneous gestures.

Or, you can open Photoshop, tap Import and Open, tap Files, navigate to the folder where your image is, and select it, a lot like using the Open dialog box in Windows or macOS.

The techniques above should let you open most common image formats in Photoshop, but I don’t think Photoshop on iPad OS can open a PDF file yet. But if all you want to is view a PDF file without editing, just tap it in the Files app and you can view it right there, without opening any other apps.

Also, all of the techniques above work with normal files in normal folders stored in the Files app. They do not work with PSDC (Photoshop Cloud Document format) files. That is because PSDC files live only in the Adobe cloud and are not seen in the iPad OS Files app, just as PSDC files are also not seen on Windows or macOS desktops (folders). This is a very important difference. In other words:

• Photoshop Cloud Documents are found only in the Home and Your Files panels on the Photoshop home screen. 
• Creative Cloud Library items can be added only to an open Photoshop document, by clicking the Import button.
• Lightroom Photos is another type of Adobe cloud storage that is not connected to the first two in this list, but can be sent to Photoshop from Lightroom on iPad OS.
• If you are storing files in a cloud-synced files service such as Google Drive, Dropbox, Apple iCloud Drive, or Microsoft OneDrive, you can open them from Photoshop by tapping Import and Open, then Files. (Note: I edited this part of the post because it used to talk about Creative Cloud Files (synced files), but that was discontinued in February 2024. The same concepts work with other cloud-synced file services.)

It can be very confusing to remember the difference between all of these different kinds of cloud storage and how you save and open files to and from each one, but that’s the way it is.