when I went clipless, I got between two cars in the driveway, held myself upright between them, and just practiced clipping in and out (a trainer will work too). Then I got out on the road and fell over at stop signs a couple of time. After that, I just made up my mind that I wasn't going to fall over again...practice practice practice.
Ethan, my nine year old son is learning to use clipless pedals. He's averaging about two falls per ride. It's really a matter of practice. Remember it's a 'quick' motion of the heel away from the bike to release the clip. It also helps to practice on grass!
They are called "clipless" because they don't have toe clips with straps. Learning to ride with toe clips - now that was a trick!
Practice putting a foot down, and then cliping back in, at every stop sign. Practice doing this without looking down. Practice doing this while drinking from your bottle. Practice while . . . you get the idea.
The best advice I got was after I'd had my cleats about a year, and still fell over...like most, I'd been told heel out at the bottom of the circle. Ed? on the BRAT last year told me to try the opposite--heel IN and at the TOP. Works for me! I was hurting so much that day I wasn't very nice toi him! My belated apologies, Ed, or whoever you were!I've not had a clip related fall since!
I practiced clipping in and out between a door frame inside my house (same concept as between two cars). I found the motion easier than many people talked about and never fell once...that is, until today! I just forgot both feet were clipped in when I came to a stop Good thing there weren't any cars coming up behind me at the time
It sounds like you need more advice. If you have a yard that is rideable, get used to the pedals while riding in the grass. Go to a school yard if you don't have a suitable yard. Doesn't scuff you up if you fall. Just clip in and pedal in your lowest gear and practice stopping and starting. Relieves the fear a bit. I trained both of my progeny like that and they still have unscuffed knees.
Wished I had gotten all this advice before I went out on Memorial day and wrecked and in the meantime broke the arm. Thought I had practiced enough, but I guess not.