Hi, thanks for commenting! What gamepad are you using? Changing tabs in the menu should work by tapping left or right on the d-pad or right analog stick and exiting the menu should always be the same button you used to access it. I will add options to rebind controls in a future update though.
As for the bombs/ arrows in the shops, they are only refills so you'll have to find the bomb bag/ bow first. The library in Goldbell contains a hint on where you should go next.