You're gonna have to go in one day. So get going..
Go in and have a chat. They're all usually friendly. Make out that you're pricing up some tiles or materials for a job, get the chat going. Look at a few displays, ask what brands they stock (Bal, Mapei/Ultra etc), tell them you're new and getting going and that you'll be using them in the future.. they'll be fine with you.
Dish out some cards, don't expect the calls straight away though.
My tip is to always keep cards in your pocket, for when you bump into people - everyone is a potential customer, pals, family, bloke in the pub... anyone