Seeking avenue to learn about bikes & bicycling

I joined this group in hopes of learning about bikes ... so as to
purchase one. I know nothing of purchasing a bike. I understand the
concepts of road & off-road & trail & dirt ...etc. But do not know
what that means as far as the different styles of bicycles -- other
than the tires are different.

Please direct me to a group or web address where I can learn about
bikes and bicycling -- and most importantly how & where to purchase.
I have never purchased a bike before -- have ridden ... but not
purchased. I am female & 50's & live in Virginia.

Thanks,
SHiRL