If you really want to enjoy it, make sure to get the bike fitted. Some of the good shops have people trained in how to size and adjust the bike to fit you -- long legs or short, how far is your reach to the handlebars, etc. It might cost a few dollars for the service. And get one from a good shop, where they know how to properly assemble and tune bikes. You can be confident that nothing sitting on the floor of a bike shop is junk or unsafe, it's just a question of your preferred style and your budget..