You most certainly can ride. The nice thing about a bike is it does not care what you look like or how much you weight. Climb abroad and enjoy yourself. Start slow - none of us started out riding 100 miles in a day. Listen to your body for it will tell you without hestitation if you are pushing it too hard or not pushing it enough. Keep a log so you can see the progress your are making (my boyfriend thinks I'm anal because I record data from every ride but it helps me see how I'm progressing). Only listen to those who will offer words of encouragement and turn a deaf ear to those who tell you it can't be done or laugh at you. Have fun, enjoy your bike and take care of yourself.