Great idea, anything which brings new blood into the hobby is a bonus, particularly if it teaches youngsters some engineering skills and r/c cars are a great example.
We at A1 Racing Club have been running beginners nights or a couple of months to get youngsters into the hobby and it has been successful, the parents all agree that they want to get the kids off the xbox etc and out doing something social so you are doing something good.
one thing that may cause issues is the grip factor, if you are going to be running on a slippy surface then the lack of grip will make it hard for the kids to get used to controlling the cars in any manner and lead to frustration from the start... maybe something to consider, carpet is expensive, awkward to store and unless you use decent stuff it can fluff up and damage bearings and drivetrain on cars plus wear fast!
for basic track markings it may be worth looking at fire hose as its easy to shape and won't get damaged by the cars... a lot of clubs use it for marking, we filled ours with gravel, which makes it hard to move if hit by cars, doesn't cause damage to cars if they hit it but it would be a pain to lug about and store if we didn't have a venue where we can leave it laid out permanently over winter.
But you could leave it empty to mark out basic tracks and simply roll it up or storage... worth going to your local fire brigade and asking if it would be possible to have some old hose (or offer a contribution to their welfare funds etc) that they have to discard after certain use or damage etc... if you explained it was for a good cause then they should be keen to help.
If not then we bought ours from a builders merchant and they do good deals if you need a good amount.
Hope this helps a little, best of luck with the venture
