Bogamil,
If u just want to have a feel of flying, go get those electric 'planes'.
Well trust me you wont learn much of RC flying from those but its just to get a 'kick' of flying something.
There are also electrics like the nitro powered ones which have 4 channels or more but they are actually some times more expensive than the nitro powered ones.
I would seriously recommend the nitro powered ones.
I got my trainer only with a 4 channel radio and i'm still using it on my 2nd plane which is a CAP232. I'm actually learning to do 3Ds with it and it is a little bit harder than if i had a computerized one but i know i'm learning more and if i get my 2nd radio(which i hope will be my favourite one..a FUT ABA9CAP) i think i'll be finding things a little easier because i have leaned the hard way.
Actually all you need is a 4 channel unless you want to do extreme aerobatics /3D and so on.