I was told that first you build your cadence then you build your speed. Work on finding the right gear that allows you to peddle as quickly as you can. Once you have your cadence down you will be able to go farther. Great choice, good luck!
Learn to use your gears. Change down a gear or two so that you are pedalling fairly quickly, but without a huge amount of resistance. Pedalling slowly but with a lot of resistance fatigues the muscles faster. Most people find a pedalling tempo of around 60-80 rpm optimal in terms of sustained output.
Check out the Spark team Slow Riders which is for the recreational and commuting cyclist rather than the all out to the wall hard core racers. Lot of friendly advice is available and some riding tips from the members.
I just incorporated bike rides into my daily fitness routine. As of right now, I get tired pretty quick, since I havent ridden a bike since I was 14. I think I have been doing about 15 to 20 minutes a session, sometimes twice a day. Im guessing I am doing about 2-3 miles. I am going to gradually add more time and miles. Anyone have any tips, stretches, exercises etc so I can get stronger each week? I downloaded a cycling app and will start using it as well but for the time being, Id like to hear some fun facts, tips, tricks etc about cycling! Its such a rush to go fast and I love that feeling!