How do I make a grid based placement system?

im trying to make a game where you can place items around, destroy them, move them or just replace other objects in the world.

i cant find a video to watch or anything, i did manage to find a old forum post from 10 years ago and tried to do what he/she said to do but i didn't get it to work, could someone help me out?

so i managed to make a placement system but it places the sprite besides the mouse pointer, and i have not figured out how to delete a sprite yet either, or how to add more sprites to place