Were is a good place to go when looking to make Sprites/characters for a 2D game (Preferably a free place)

So I have been working on a game, It is just a mini project (so I get the basics of Unity down), and I can't figure out were to go to make my own character/sprite, I've looked and can't find any good place and many people have said to just use already made ones but i want to make my own, any ideas on were and what program i should use? Thanks!