Taught myself to ride at 27! Seconding the above comment about searching online...I read every article and watched every video about adults (and kids!) learning to ride. You may also want to check out any local bike clubs as sometimes they host clinics for beginner riders.
I ended up buying a cheap mountain bike (wider tires) and helmet from Walmart and taking it to a deserted trail area to ride. Bring down the seat as low as you can (so your feet touch the ground) and remove the pedals if you can. Start on a slight decline, so you can build momentum and work on steering before you bring in pedaling. Push yourself along and just coast, get used to shifting your weight and turning the handlebars. It sometimes helps to thing of steering along a swooping “s” as opposed to a straight line. And it seems counterintuitive, but if you feel yourself start to fall, turn your handlebars in that direction and you’ll straighten out! I was able to teach myself to ride in about an afternoon and now I’m addicted LOL.