Learned my younger sibling got autism

Recently learned that my 10 yo sibling has autism, and it's been on my stress list. He's always had trouble getting along with some kids in his class, and his grades were low due to the lack of focus, but he's a great little idiot. I just wanted to ask for tips on how to support him and help him whenever he encounters things related to this topic in the future, or maybe even daily life, cause I don't know if things will get easier for him. I just want to see him grow up happy and have a bunch of friends. Sorry if this sounded like a little rant but I would really appreciate any tips or advice on how to help him out. I also know little to nothing about how autism works, so please let me know if there's anything I should be sensitive towards or anything like that. Please and thank you.