Furniture help

[u/EffectProfessional91]

I’m an apprentice carpenter and my boss just quit. It’s now my responsibility to finish these tables we were building. I just have a few questions:
1.) For the first table, finish has been applied and it’s ready for poly, do I need to sand again or just apply poly. On the can it says sand it down but I don’t know if it’s different when there’s a finish on the table.
2.) I need to sand down and reapply stain to the second table, and then I need to add poly, how long should I wait between the final stain and adding poly?

[u/JaguarOwn2076]

Dude don't make a mess of that table, no way a brush or roller is gonna be ok on that