Shimano Acera hits spokes. Which screw to turn?

You need to adjust the L-Limit screw - Have a look at this Park Tool guide.

The problem may also be a bent derailleur hanger. Checking and, if needed, fixing this is best done with a specialized tool, and is quick and easy if you have that tool. While it is possible to make the check and repair without the tool, the precision is nowhere near as good. This Park Tool guide might be helpful

Given that it's a new bike, I would do a sight check for a bent hanger; if obviously bent, send it back to the shop. If not, have a go at adjusting the L-Limit. If it does not all come together easily with smooth shifting and good spoke clearance, get the shop onto it as it could still be a bent hanger. Without the tool, it takes a good eye to spot a small error.