Recommend something EASY

I would just set the gaming level to the easiest levels on just about any FPS - and get used to the game. As you play you will get better and better. You should naturally progress. Try any Halo, Destiny 1&2, Borderlands, Any Battlefield, Gears of war.
Another tip is to find some new friends on xbox live and play in co-op with people willing to let you learn and get comfortable with the game.

What have you played already? Some games are very different and you might need to find something that allows difficulty changes.

Id say you will love Far Cry, especially taking NPC's with you into battle, if you go down they will revive you and you can play at your own pace

Some of my favorite are:

• Anthem
• Bioshock
• Borderlands (Any in the series)
• Fallout (Any in the series, mostly recommend Fallout 3 or 4, if you want to play with friends you’d have to go with 76 but that’s a hit or miss for some players)
  
• Far Cry
• Half-Life
• Halo (Any in the series)
• Metro

Try Destiny 2.Its a bit easy to complete the story.