you pedal and steer so you dont hit people or cars
It is up by brake pedal bracket to the left of it take cover off at brake pedal bracket in the process of it right now.
The same way that you fit every other bike pedal. Just remember that the left side pedal has a reverse threadand has to be turned clockwise to loosen. Oh, and the old ones are usually stuck pretty good.
The same way as you remove them from just about every other bike, you unscrew them. Find a fitting tool(some have wrench flats, some require an Allen key), then unscrew. Keep in mind that the left pedal has a reverse thread, and that they may be well and proper torqued down.
Don't know what you mean by cassette cranks, but to be able to back pedal you'd need to get another hub for that bike. It's probably cheaper to find a complete new rear wheel than to rebuild your current wheel around another hub.
Depends on how fast you pedal. As it is a single gear bike. BMX bikes are made that way because if crashed, the bike would be 10 times harder to fix.
A single gear, usually called a single-speed is a bike where the the rear wheel will always turn the same amount for one turn of the cranks. Means that the bike will be simple and rugged, but that the only way to climb a hill will be to push harder and the only way to get more speed is to pedal faster.
If it's all the way over on the left, it's the parking/emergency brake. You set and release the parking brake with this pedal. If it's right next to the brake, it's a clutch.
There's no way of telling, as that would depend on the wheel size and gear ratio, which can vary from bike to bike. The Online Gear Calculator (in the relevant links section below) is very useful for calculating the distance traveled on a single pedal stroke, if you have some parameters to input.
Depends on how much too big they are. Not being able to put both feet on the ground with your butt in the saddle is perfectly normal, and is to be expected from a normal looking bike with some utility value. It needs to be that way for you to get a decent amount of leg stretch in during the pedal stroke. The way to get on and off a bike is to stand on the pedals and leaning forward a little while getting in and out of the saddle. Then you should preferably have space enough between the top tube and your crotch to be able to put at least one foot flat on the ground. If it's still too big (crotch hitting fram with feet on the ground) it isn't really advisable to ride, but you can still get on and off by leaning the bike over as you get up on the pedals. Then get into the saddle after you've gotten the bike moving. If you have to tilt your hip left/right to keep your feet on the pedals then your saddle is too high.
Some do, some don't. Although these days training wheels aren't considered such a hot idea. Basically they don't teach the kids to balance, they keep riding the bike as if it was a bigger tricycle. When the trainers come off the kid still has to learn to ride. It usually works far better to start off with a scoot, or runing bike, a bike w/o pedals. The kid straddles the bike and kicks him/herself forward. That way, they pick up the balance real quick and then has an easy transition to pedal bikes.
Turn key on do not start. Push the gas pedal all the way to the floor 3 times, make sure you let all the way off of the pedal each time. Then turn key off and then start engine.