Hey guys I need help with my twitch background.

Its a basic Assassin's Creed Revelations pic with Altair and Ezio in it. I kinda don't want it anymore because it doesn't have my own feeling or design to it. So i have MS Paint on my computer and just downloaded Paint.Net now can i get really good background pics from those 2 programs and if not is there someone that can take a twitch background request for recommend a program that i don't have to pay for (because I'm broke) that can get me good Background pics