Once you beat it on Normal, try Heroic. By the time you're done with the campaign twice you should be a lot more comfortable with FPS controls on a controller.
I'll second RobertR1 here, and add that imo the game is even more enjoyable after you've been through the campaign once. Once you sort of know where to go and what to expect, you can just unleash. For me, this is when Halo is at its best.
