Just restarted my game after the 2 characters I made were pretty much exactly the same as the 2 you recruit in game. On to part deux
That's really not necessary. The game is entirely classless, and you can advance those two companions (as well as your own characters) however you see fit.
Also, later on in the game (perhaps in the middle of the first area), a
wealth of henchmen will become available; by that point, you can make whatever party you want - and you'll have enough of an understanding of the game to choose properly.
Don't ever feel pressured into having a specific party composition.
So yeah..where can I store stuff?
Also for my mage does the weapon damage matter? (Like does magic dmg scale off of it?)
You can store stuff wherever you want, though you will get a specific area for storing things at some point in the game.
Staff damage matters for your ranged staff spell, but nothing else I know of. You'll primarily want the staff you have because of the element it uses and the bonuses it gives. I've personally found directly damaging enemies with the staff as a last resort tactic, because the damage they deal is rather poor.
Edit
My friend just gift me the game, i am so lucky.
Any advice starting the coop before the solo experience or it's the same thing?
Lucky you!
Solo and co-op are the same game, the only difference is your co-op player will control some members of your party. You can set who controls what in the ESC menu.
One thing you might not know about co-op is this: everything is set by the host - you're playing in their game, and nothing is imported from another player's game. This means non-hosts cannot make their own characters
unless they join during character creation, in which case they can make their own at the same time as you.
Also, if you begin a co-op game with someone, it's probably best if you only play that game while they're present - for consistency.
Divinity: Original Sin is fully designed for either co-op or solo play.