There are so many variations on the bicycle theme today that it would be impossible to advise you adequately well in a short post.

My advice is to first shop for a bike shop. Visit all of the bike shops within range of where you live. When you find the right one - one that has a staff that you can identify with - that's it. Once you find the right shop the rest is easy. Find a brand of bike that they carry, at a price point that you're comfortable with, and you'll never go wrong.