Hello, welcome to Spells of Magic!
First of all I really want to say how happy I am that you are open about your autism - I work in special education and I've seen how hard it can be to open up and admit to something others may perceive as making you "weird." I'm glad you accept who you are. It means you're already way ahead of most people. :)
About your demons, I can certainly see why you might have questions about using white magick. You probably shouldn't do overly heavenly things like invoke angels, at least not without asking your demon friends first - you never know, there might be a few angels in heaven they're on good terms with. But most of what is considered white magick is just beneficial magicks like healings and blessings. Since these demons were kind enough to aid you when you were in need they're certainly not against kindness or benevolence itself. You may need to find alternative rituals or spells since most are written with white magick in mind, but if a demon helped you he or she shouldn't mind you helping others in turn.
I'm glad you're here, I hope this helped, and it is my deepest wish that you and your demonic friends and allies all flourish in the weeks, months, and years to come. :)