Assuming you can balance on the bike and go forward, I'd just start riding. Grassy surface if you have one, empty spot like a parking lot if you don't. Don't go into traffic until you feel confident.

I worked on specific skills (still do). Getting on and off the bike, stopping and waiting (like at a red light), and weaving around obstacles are a few
suggestions.

As FunSize mentioned, the learning curve is pretty fast.

I'd say just do it, and ask here about any specifics that you can't figure out on your own.