I need help setting up my new iPhone

Start here: https://support.apple.com/en-us/HT202033

Can i ask somebody in the store to help me set up a new phone from apple store.

How can i return the new phone i just purchased.?

Yes you can ask at the Apple store for help setting up your new iPhone.

Take it back to the store where you just purchased it.

You will need all accessories and probably the box too.