I have a thrift store that has a makeshift kitchen for subs or pizza we may start to incorporate that into our store, can we have the bathroom next to the kitchen space, both with separate entrances but next to each other.

Do you have a permit for a restaurant? Local code will determine allowable location.

In my area the answer is yes. But check with your local building department. Also, as Brain has suggested check to see what food license and permits you need to start a restaurant. Good luck, Tom