Hi and welcome to these forums

First off you want to use a good wifi router with the mixer. That will allow remote control of the entire mixer, and of individual aux mixes via smartphones and tablets.

Then you want to check if the mixer gives you enough physical aux outputs. The 24R has 12, which makes 6 stereo mixes (for in-ears). You can have 4 more auxes but that requires an NSB stagebox.

And then you have to invest in your monitor systems, wired or wireless. A wireless transmitter will connect straight to the auxes. Wired buds needs a headphone amp (e.g. on a belt clip) for every band member. With medium impedance (60-150 Ohms) headphones you may get away with driving them straight from the aux outputs (using a Y-cable), but use proper headphone cables, keep them short, and don't expect too much. Or you can use the EarMix 16M for wired monitoring. These don't use the aux outputs but connect via AVB to the mixer.

Hope that helps

Fantastic... great... we can proceed then....
Cheers.

Last question. We shall use Qmix-UC for each musician on their smartphone. UC surface on a tablet. We shall buy a wifi router connecter to the rackmounted. And Universal Control on PC. Is it right UC offers same functionalities than UC Surface ?
We want to use PC more than Tablet for our first lives.
Cheers.
Hervé