A Shop is a place where you can buy everything with gems. In Shop you can find a VIP shop where you can buy stuff for discounted prices and some items you can buy with resources like action points and speedups. The shop is restarted once a week.
To buy more advance items like golden sculptures or 24 h speedups you need to get the VIP level.
I would advise you to not spend gems in the VIP shop. Only buy stuff that cost resources because there is a better place to spend gems.