#1
My friend will lend me a Behringer USB console like this ONE HERE!

Is it possible to connect my Vox AC4TV Combo directly to the mixer with the cabinet output ?
#2
Dont do it. The cabinet out on the amp is a much larger signal than a line out, which is what should go to the console. You'll damage something by doing that, probably the console and the amp because the amp wont be 'seeing' a proper load and will most likely fry your output transformer. And even if it did work, it probably wont sound to good.

You'll need to get a microphone (a Shure SM57 is commonly used for amps, and isnt too expensive) and mic the speaker.
#6
some amps have line-out. that's what they're used for.
could just get a mic and cable, and rig it up. and SM57 will probably do for most cases.
#7
Does it have a direct line out? If so, then you can go from that into the board. If not, then don't try it.

Micing a guitar amp sounds better anyway.
#9
Mic'ing is a better idea. It's safer and it gives you something much closer to the actual tone of the amp. The power amp, speaker and cabinet all affect the overall sound.
Even if you did have a line-out, the signal coming out of that would only be the result of about half your amplifier's components.