So i just started a clan, got a few members and im wondering a few things.

Can we practise in any other way than challenging other clans?
Can we practise Clan-Only? Can i create a game for Clan-Only game to run around maps and herp derp?

What are the perks of having a clan? Is there any? Explain to me how it works!
I did make 2 teams and another member leader of it, i wanted to play 2v2 but i dont understand how. I couldn't challenge his team.
Is it cause we are in same clan?

Thx.