The only way for you to get confident is by going out and riding.
I've been competing for a few years and my wife just got into cycling last season, she's come a long way, it's really a matter of putting in the time.
Go out and ride around the neighborhood to get your confidence up. I think people overthink the sport, it's really very simple: you press the pedals and it goes forward, you turn the handlebar and you go left/right 🙂
If you're talking raising your fitness levels, then that's a whole other bag. But I'll tell you what I've told recreational runners who I've trained, just go out and enjoy it, everything else like weight loss and fitness is secondary and will fall into place if you're putting in the time. The point is, go out and have fun! It's the same with cycling.
For now, without getting too structured, I would say ride as often as possible and sprinkle in some hard efforts during the week (maybe race the kids)
Have fun, take pics and keep us posted.