I'm new here and I'm a bit confused on how the animation works, for instance how to choose the sprite sequence and to inform the size of the sprite so it doesn't look like a huge .jpg

spr(1+t%60//30*2,x,y,14,3,0,0,2,2)

the code editor gives you this line, but I still can't really figure it out.

Feeling a little dumb, but the answer is here:

https://github.com/nesbox/TIC-80/wiki/A-step-by-step-introduction-to-TIC-80,-Part-1:-The-Default-Cart

crotalus93 It's works!