WHOA
You should NOT start paying for a store. As a new seller with a feedback of 2, you will be under strict ebay sales limits (usually 10 items a month, $500 a month max, and several other limits in categories. You need to get your limits totally removed before you consider a store at all. Stores cost at least $15 a month, and the small amount you save in listing fees will not even come close to paying for them...AND you will lose the 50 free listing fees a month you get as a regular ebay seller. Opening a store WILL NOT get your limits removed or increased.
If you doubt it, check out the fee illustrator for stores to see what it recommends.