Hello! To start, I am trying to get a fitness routine going and I hate running. Always enjoy bikes against treadmills and running. So I want to invest in a bike. 1. I will be biking on paved black paths and dirt paths where I would ride. 2. Is there different "size" or "height" bikes? I'm 5' 2" and 120 pounds. I don't want to end up having a hard time getting on the bike. 3. Interested in schwinn under $250 but open to other suggestions in the price range. 4. Looking to use it for recreational fitness not for races...yet! Basically what do I need to look for in a bike? Anything to watch out for? Warnings? Any help is great thanks!