Answer a few questions first.
Can I drive a manual transmission ?
Am I reasonably coordinated ?
Do I panic easily ?
Most bikes are manual transmissions, with a few exceptions. Unlike a car the "shift pattern" is just up and down with the left foot on (or under) the lever. The clutch is the left handlebar lever (the one that you thought was the rear brake like on your old Schwinn).
Taking off from a stop can be a jerky,lurchy stuttering thing till you get the hang of it.
Experience with a manual transmission helps, but isn't required.
Can you manage to coordinate your right side hand and foot and left side hand and foot ?
Your brakes are on the right.
R hand front, R foot rear.
You have to balance the input for a controlled stop.
Problem is, the throttle is also in your right hand and the clutch is in your left.
There are a number of things you must not do.
The one thing you cannot do is put your feet down trying to stop the bike if you think its getting away from you.You are going to get hurt doing that. Those old bicycle reflex's come back sometimes, you have to control the panic.
Seek a driving school or a friend with a smallish bike.
It's not really that hard.
I find most people can get the basics in 1 weekend of practice.
Enough to maneuver well enough to practice with confidence in a parking lot.