Bike Forums - Hello everyone, i am new here from Chicago Illinois

hello everyone, my name is Robert. I am looking for a bike for this summer and I don't know which way to go. I have a budget for around $500.00 I know it's not too high but I thought this should get me a pretty decent bike to start off with. I have a few friends who ride. One says Trek and one says Cannondale. I say I don't have $2000 to blow on a bike LIKE you guys did. So I don't want to pay $200 FOR THE BIKE AND $300 FOR THE BRAND NAME, YA KNOW? I am open to all different bike brands, I just want what's best for me. I am roughly 6 ft - 6 ft 1" with a 33" inside seam of my leg. I just bought a house that's 3 blocks from a huge bike trail. 99% paved trail. I hear a lot about getting a carbon fiber fork for ride comfort. this trail is very long. Just as a starter ride I rented a bike and went 40 miles with my girlfriend. we went about 17 miles to a few towns over and ate lunch and drove back. my complaint was cramps and a little uncomfortable for the long ride. I had to stop a few times each way to stretch. This is most likely normal but then again I don't know anything about Bicycles. I was hoping to get some advice on what I should buy. I would rather not put the bike together but I am willing to do so if needed. I have full faith I can perform the task but WHAT I don't want to have IS missing pieces to the bike and I know I would be fully unaware of this. I appreciate any help like I said I am a novice at best and would really like to buy a bike soon. Thank you for reading, looking forward to your suggestions