Get a cheap bike and try it. Find someone to help set up the bike.
The seat will bother you for a while, live with it, it gets better!
I started a year ago at 288, rode 12,000 miles last year, now at
216.
You just have to want to do it. and then go out and do it.
You don't need to spend a lot, I started on an eighty dollor
Walmart bike, wore it out and sold it at the yard sale, got
a Trek now, older bike, but perfect for me. Look around for
a used bike, can you do any fix'n on them? The is a section
here to get you started, few tools required. They don't need
to be high end stuff, Nothing that big or hard on a bike. Allens
and some screw drivers, and a cresent will get you going.
Welcome BTW!