You can enter the mists and roam around by yourself, looking for enemies players to kill. Then you will be ganked by a WvW-specced thief who can one-shot you from stealth.
You can enter the mists, find the Zerg for your side, and then go on a rampage against an unprotected enemy outpost, taking it easily over from the PvE enemies there. However, the enemy zerg then takes your unprotected outpost. Basically a never-ending, tail-chasing charlie foxtrot.
TL;DR: don’t bother with WvW.