Is it a hit or not?
 

first and second are occupied and the batter hits what appears to be a single to left field, but the runner on second base is forced out at third. Does the batter get credited with a hit or a fielder's choice?

No offense, but we're umpires, not scorekeepers. Our only concern has to do with who's safe and who's out.

You sorta answered your own question when you said force out. It doesn't matter if the play went 6-5 or 7-5. Still a force out and a FC for the batter.

Speaking NFHS, it is a fielder's choice, and the batter is not credited with the hit. 9-3-2a & c.

Some of us want to learn the entire rules book, not just the parts pertaining to balls, strikes, and outs, and that includes the scoring and record keeping rules.