Can't close all tools

Your tools are sticky, so your last tool will still be active. Use the letter v to return to your move tool... it's a quick, easy fix. You can also hold down the cmd/cnt key when using a different tool to temporarily access your move tool. 

If you can’t get to commands, that usually means a tool is in some kind of mode, like it’s waiting for you to apply a pending edit. To see if that’s what’s happening, look for two icons in the options bar that stand for Cancel and Apply. They appear only when a tool edit isn’t committed yet.

You can then cancel or apply the pending change with the mouse/trackpad or keyboard:

• With the mouse/trackpad: To apply the currently pending change, click the check mark; or to cancel it, click the circular “No” icon.
• With the keyboard: To apply, press Enter or Return. To cancel, press Esc or Command-period (Mac) or Ctrl-period (Windows).

After that, you should be able to get to commands again.

I don’t know why a tool would be in that state if all you did was open a file, though. Unless that is a Catalina problem I dont know about (my Mac is still on Mojave). Anyway if a tool seems to be blocking things but you aren’t editing, you can get out of it quickly by pressing Esc.