My first level 80 character
sPvP is completely separated from WvW and PvE. You wont take your gear there.
In sPvP everyone is lvl 80 with full access to traits and utilities and can pick from the same gear stats (just looks change), etc. So if you want to go sPvP you dont need to lvl or gear or anything…
WvW uses your character PvE gear, traits and skills, but your lvl is always 80.
If you follow the zerg there (depending on your server and timezone) you don’t really need good gear, skills, build or brains. But having those DO help in any case.
Go around on wvw a bit and figure what you like (folowing the zerg, small groups or solo roaming) then search the forums for suggested builds/gear and adapt them to your needs.
Guardian is a very adaptable class that can perform many different roles (even run away, if you have the right combos).
Good hunting!