You set the resolution in the project settings under window size. That being said, why on earth are you making your game 32 X 32.
That being said, this resolution is far too small and it doesn't matter what you do, it probably will never look good full screen. To play the game at 32x32 resolution not scaled, the player will have to strain to see anything and scaling it up to a playable size will just make it extremely pixelated. If you are looking for a retro resolution, you could try shooting for an early pc game resolution like 320x200 or even 160x144 which is the original gameboy resolution.
Thanks a lot for the help, i know it`s kinda crazy but that`s the challenge of the game jam (and one of the rules), its called low rez jam, i want to give it a try. It´s intended to look very, very pixelated, and it has to move acording to the pixel grid.
Thanks again, i´ll take a look if i can do it.