Congrats first of all. What kind of genre's do you enjoy playing? The easy thing to suggest is getting Game Pass. They currently have $1 for 3 months of Game Pass Ultimate. If you prefer buying games, check out MCC, Forza Horizon 4, Gears Tactic if you enjoy strategy games, Ori 1 and 2, Quantum Break, and a bunch of 3rd party titles have received FPS boost. You can also play plenty of great BC X360 and Xbox titles for cheap.
Here is a list of fps boosted titles you can check out. Games Featuring FPS Boost - Xbox's Major Nelson