Oh my...what have I gotten myself into!

[TrekTheKaty]

Queen Carlotta, Welcome! Don't worry about being slow. Just get out there. Cyclists are friendly. We were all slow once! Do you have a park with a couple mile loop nearby? It's a nice way to get started without getting too far away from home/car.

Consider everyone's recommendations about used bikes. A few months on a cheap bike will make your more educated about what you like and dislike. By then you should be hooked and will be ready to move up

tharley, I started cycling because I had a bad back. Like you, I chose a hybrid with an upright position. However, after test riding a road bike, I realized sitting upright actually caused more jarring. I'm now more comfortable on my road bike--be very honest with the LBS about your back problem during your test ride and fit. You can get a road bike with a more "upright/less aggressive" position.