Job as an introvert

I'm 20 years old & have never had a job due to me being pregnant at 17 & had my son at 18. I've been a stay at home mother since we had no one to watch our son. My bf may end up quitting his job so I may have to start working so I'm wondering what you guys would suggest or what you yourselves had as a first job. I'm more of an introvert, I have a bit of anxiety when it comes to me being in the spotlight or talking to new people but I know I have to toughen up bc that's how life is. I know I wouldn't want to be a cashier because I'm not good with confrontation if it comes to me giving them the wrong amount. I'm possibly looking at sewing or stocking item on shelves, possibly helping out customers with things they're looking for? Also how old were you when you had your first job?