Understand this:

The "nofol self" command is important. There will be
thieves and assassins that will simply follow you around
otherwise. Once you level into the 30s standing around in
cities/guilds is a quick way to get PKed.

With my first char, a felar warrior, I had a hard time
understanding why I kept getting assassinated at every turn
until I figured this out. Assassins in your general area will
"stalk" you (after they are level 35+). Meaning if
you stand around too long they will likely kill you in a
single strike, for example once you step out of your guild to
go rank or whatever.

This can be avoided by moving quickly from place to place.
Making sure no one can follow you super easily (including
thieves that will lurk around waiting for a good chance to
trip/kill you). Assassins and thieves will have to step out of
hiding on water, so briefly going onto the river along the
eastern road or hanging on the oceans a bit can help mitigate
some of these issues or to help inform you if you're being
followed.

Warriors are strong in the early and mid ranks. Toward the
late 30s early 40s you may find you get your butt kicked.
Though once you are up against all the heroes this will be the
case for a while with pretty much any class (especially as a
newb), hence the benefits of being able to hide/camo/duo when
you are still learning the game. A big part of the learning
curve is knowing which matchups/situations are win-able and
which are a death trap. This takes a lot of practice and is
something you learn again with each new class you try.

Good luck. Expect to die a lot for quite some time but know
that eventually you will start kicking butt too if you stick
with it.

PS- I also think an assassin or arial-thug thief (battlerager
defender) would be a great build to learn/explore, but you may
find that getting a group to rank is much easiest with an
assassin/warrior/shifter/ranger, in which case think about
nexus or fort as cabals.