Generally with modern R/C systems:

Channel 1 is primary turning which on a heli would be the right-left cyclic (ailerons on fixed wing)
Channel 2 is primary pitch This is the fore-aft cyclic (elevator)
Channel 3 is throttle
Channel 4 is secondary turning ... tailrotor (rudder)

from here it varies by radio sometimes varying within a brand of radios... Some use channel 5 for collective pitch others use channel 6.

The throttle and collective pitch channels can be swapped in some setups. (and as long as you program the mix appropriately... it doesn't matter really.)

Generally, the unused of 5/6 is programmed to act as a trim to the collective pitch/throttle curve.

Its helpful to program in a bit of exponential on the cyclic controls to make the stick "soft" in the center. not much... just to take a little of the wiggle out when your hand shakes. (some call it positive exponential, others call it negative exponential... truth is.. a mathemetician will call it negative.)

Then you get into the programming of the throttle hold function, the idle-up function, the acrobatic throttle curve... (which increases throttle when you go into negative collective pitch so you can fly inverted...) Most of the details on these settings you can ignore till you learn to fly... but make sure the throttle hold and idle-up BOTH are set to keep the engine running. (also make sure the idle up doesn't rev up to high... the thing should stick on the ground when in idle-up.)
****

Now... before lifting off the first time... get an instructor. If you goof badly you can kill yourself with one of these things.