How do I make a shop/Characterselection menu?

I’m currently working on a alien survival game and right now I’ve bumped into a huge problem that’s stunting my progression.

  1. What do you want to achieve? A creature selection menu that works pretty much like the other known creature-survival games to where you can buy, select, and spawn in with the bought creatures.(example: Malgamation’s island, Creatures of Sonaria, etc)

  2. What is the issue? I have no clue on how to start or by most make it

  3. What solutions have you tried so far? I couldn’t find any tutorials or posts that relate to making something like this…

Heres a screenshot of the shop. Please give me your opinions on it too:

(Mind the possum images, I just use them as place-holders lol)