Help in GameMaker

Share your creations!

Just a little reminder that UTG is still hiring... No one has joined yet except for @Akl00 (one of my friends). If you know someone or you wanna join, the form is still opened!
https://docs.google.com/forms/d/1Do75Tr4k5lvgenS4aQpmV-Gt53aibWV…
I'm trying to make a Deltarune fangame and I need help learning how to code in GML
For people wanting to make a Deltarune fangame, Kris' sprite size is 18 in width and 36 in height, however ingame the sprites are scaled up by 4 times.
Question for a Deltarune fangame I might make, are the floors and backgrounds in Deltarune tiles or whole textures made for that specific room?