@MaeniGram I usually go with Clip Studio Paint, even without using its animation tools you can make cool stuff with it.
CSP is paid, so if you don't have it, it's worth to wait its discount (these are pretty frequent and makes the program cheap), otherwise you can go with Krita as well, or blender grease pencil if you feeling spicy (I haven't tried blender yet, but i once saw this cool tutorial and might give it a try some day https://www.youtube.com/watch?v=Dz7V0_qn1Eg).
Hairic
Ehi, can't animate for you but I can give some pieces of advice:
if you go to the Friday Night Funkin github page you can easily find the sprites of all the character and there you can have an understanding of how the animation is composed (for example these are the boyfriend images (https://github.com/ninjamuffin99/Funkin/blob/master/assets/shared/images/BOYFRIEND.png).
You should divide your sprite in parts so that you can rotate, scale or even swap them to make the different animations. It ain't easy but its learnable. You can even put that image sheet in a lower level with low opacity to have a reference.
I hope this could be of any help.
MaeniGram
Thats what i've been doing, just not very well. Do you know of any program recommendations that could help with the process?