well, I have to admit seeing decent numbers of fractured collarbones and wrists, and the occasional serious trauma among people learning, so first get best helmet you can find and protective gear.
You could try a hub driven electric board, supposedly they can be freewheeled without the motor like a heavy passive skateboard to increase your practice time, which musicians and gamers call shed time or seat time
I believe with good brakes and good skills, an electric skateboard is probably safer than riding a bike if you keep lower speeds and learn how to roll instead of just flopping/falling on the ground but a passive skateboard with no brakes is clearly more accident prone.
You could try a hub driven electric board, supposedly they can be freewheeled without the motor like a heavy passive skateboard to increase your practice time, which musicians and gamers call shed time or seat time