If your system requirements are OK, try resetting your Photoshop preferences, which you can find under the General tab in Photoshop preferences.
If you can't reset your preferences because you can't launch Photoshop, do it this way:
Close Photoshop then hold down Ctrl + Alt + Shift (Windows) or Cmd + Ctrl + Opt + Shift (Mac), and relaunch Photoshop. Respond in the affirmative to the dialog asking if you really want to replace the preferences.
Uninstall Photoshop, using the drop-down menu in the Creative Cloud app (see screen shot below), if after reinstalling Photoshop you have the same issues, uninstall Photoshop again and run the Adobe Cleaner before reinstalling Photoshop.