Help on pve&pvp characters

So, if i start a pve character and unlock places and get skills, when i start pvp do i have to lvl my character from lvl1 to 20 again and are the skills and places avaible if got in pve?
Is there a big difference do i start pvp straight away or pve first?

This may sound very noob, but I've just been thinking about buying this game... and I have no sense about those pve and pvp things(I know what they mean/are, but don't know how do they work in use), just played MS before and other more..much more simply online games.

P.S. what are those mo/r, r/mo etc. things?

One could argue whether or not you should make a PvE or PvP character first, so I won't give my opinion on this. But when you make a PvP character, you will have any skills you unlocked in PvE and by spending your faction from PvP to unlock skills from balthazaar. PvP characters always come lvl 20 when you make one. Mo/R, R/Mo, W/Mo, etc...all correspond to their profession. Mo/R = Monk primary and Ranger secondary (Monk/Ranger) and so forth. The number next to those abbreviations corresponds to the character's level.

Ok, now all is clear. Thanks a lot!

Just for the record...

A/E Assassin/Elementalist
A/Me Assassin/Mesmer
A/Mo Assassin/Monk
A/N Assassin/Necromancer
A/R Assassin/Ranger
A/Rt Assassin/Ritualist
A/W Assassin/Warrior

E/A Elementalist/Assassin
E/Me Elementalist/Mesmer
E/Mo Elementalist/Monk
E/N Elementalist/Necromancer
E/R Elementalist/Ranger
E/Rt Elementalist/Ritualist
E/W Elementalist/Warrior

Me/A Mesmer/Assassin
Me/E Mesmer/Elementalist
Me/Mo Mesmer/Monk
Me/N Mesmer/Necromancer
Me/R Mesmer/Ranger
Me/Rt Mesmer/Ritualist
Me/W Mesmer/Warrior

Mo/A Monk/Assassin
Mo/E Monk/Elementalist
Mo/Me Monk/Mesmer
Mo/N Monk/Necromancer
Mo/R Monk/Ranger
Mo/Rt Monk/Ritualist
Mo/W Monk/Warrior

N/A Necromancer/Assassin
N/E Necromancer/Elementalist
N/Me Necromancer/Mesmer
N/Mo Necromancer/Monk
N/R Necromancer/Ranger
N/Rt Necromancer/Ritualist
N/W Necromancer/Warrior

R/A Ranger/Assassin
R/E Ranger/Elementalist
R/Me Ranger/Mesmer
R/Mo Ranger/Monk
R/N Ranger/Necromancer
R/Rt Ranger/Ritualist
R/W Ranger/Warrior

Rt/A Ritualist/Assassin
Rt/E Ritualist/Elementalist
Rt/Me Ritualist/Mesmer
Rt/Mo Ritualist/Monk
Rt/N Ritualist/Necromancer
Rt/R Ritualist/Ranger
Rt/W Ritualist/Warrior

W/A Warrior/Assassin
W/E Warrior/Elementalist
W/Me Warrior/Mesmer
W/Mo Warrior/Monk
W/N Warrior/Necromancer
W/R Warrior/Ranger
W/Rt Warrior/Ritualist

Sorry if this looks spammy - I got bored and just wondered what all the Profession permutations looked like listed.

Mindboggling...