@skydriller the Zoe has a remote key which is sensed by the car from a distance (has a transponder), has buttons on it for locking / pre-heat / open the charging flap, and if you press the tiny button on the side of it, you can pop out a physical key for when the remote's (or car's) battery has died.
The keyless system apparently allows you to walk away from the car with the key in your pocket and it should self lock. When you return, the key is detected and you can press a button on the door handle to open. You can also start the car if the key is detected within the car. Useful for when in work, at a supermarket, going flying.
For this car, if you use the keyfob's button to lock the car, it disables keyless use. This is important when you're at home, so fairly close to the car, because although it is almost impossible to hack the encryption between key and car it is easy to "relay" the signal - so make the car think that the key that is hanging in your coat pocket in you hall is actually inside the car. With such a device, a criminal can pretty much just walk up to your car and start it. There is then also a slot to put the key into.
Worth saying that this sort of thing is common on lots of types of car from multiple manufacturers - it isn't special for electric or Renault.
Start is a Start/Stop button beside the steering wheel. It checks that the key is correct before starting up various systems. My other car - a 12 year old diesel Honda Civic has push start too - although that does start the engine!
My electric car has a single gear transmission, controlled in the same way as an ICE automatic (P,N,R,D). There are various gear combinations within various electric cars.
Taking your foot off the accelerator feels like engine braking with a diesel. If you press the brake the speed reduces more quickly. There are profiles in place which govern the "feel" of these ensuring they are consistent - they aren't directly controlled. So if batteries have space, energy is recovered by the motor back into them when foot is off and further when braking (more than 30kW towards the battery). If batteries are full, or if more braking is required, calipers tighten on the disks to slow you. Different cars have different "profiles" - I suspect that in time cars will allow you to change "profile" (like the Nissan E-Pedal
If you passed your driving test in one, you would be restricted to automatic cars. There are a number of driving instructors now using electric cars round my way as the fuel saving is significant, and much of their driving is slow around towns so they get good mileage.
I suggest you go to a showroom and try one!