Just jump into PvP mate. Yes, you will run into the odd jerk (or 10), but the more you play, the more you'll figure out just how different people are as opposed to bots (and the more the Matchmaking system will understand what quality of players to match you with).
Just get in there. Don't rage, be nice to your fellow man and you'll do fine.
Oh, and in early levels like that, just pick what you want. two top, one mid, two bottom. (unless one of you can jungle) - I remember back when I was down there thoguh, and Junglers tended to punish their own teams more than anything as the lack of runes made them poor junglers, and the inexperienced 1v2 fellow at the top got destroyed.
To answer your questions specifically though:
*Do i need to know all the champs and what lanes they are better in before i start to pvp? I am ok against beginner bots but get lit up most the time in pvp as of now. Maybe i should try the intermediate level 1st.
As a general rule of thumb, AP goes mid, Ranged AD goes bot. Outside of that, particularly at level 14, it's a lot more chaotic that at level 30.
Keep practicing against people, two things will happen. You'll improve AND matchmaking will start matching you with players of your level- even as you start to improve.
* I play create game a lot is there anyway to make the bots intermediate level?
When you create the game, you can select beginner or intemediate level.
* Do i need to be a pro before i try and play normal pvp?
Nah, just get in there!