Hi, I'm 52, bought my bike back this past March. You'll have a blast, I promise.
I think a bike shop might be a better idea, the people there would be able to steer you in the right direction. I had never used gears before either, had the bike shop explain it and then went out and practiced! I figure at my age if I can go out and buy a bike in March, do RAGBRAI (485 miles over 7 days) in July, anything is possible. Anytime I've had a problem I take a look at the website, get inspiration and keep on going.
Geana