Okay, I have a bit similar problems so will share my point of view

Success in PK:
My character is a totally unbeatable beast and even IMMs logout in terror when I awake. This will be in a future. To prepare myself for this I am playing now with chars that are good in exploring. You should know what gear to get, where preps are and so on.

Success in exploring:
Play bard/good conjurer/defensive warrior. That what I am doing.
They all are really welcome in groups. Bard has good support songs and can tank in some cases. Conjurer past 35 and warrior are good tanks and deal good damage as well. So its pretty easy to rank. And they still good in exploring. Trannie is welcome in groups and can explore (just explore, not get all those shinies) in duo. Do not play offensive classes - axe spec or offens. shifters. Do not play mages who need preps.

Empowerment classes are have strict code of behaviour and enemies. And it consumes time, so I do not suggest them.

So you rank to past 40th and can start exploring even alone. With invoker/offensive shifter it will be easy, funnier, and not so boring cos you have a companion to chat and discuss something with.

Success in RP:
I personally start to play without any RP, and my role is drawing in all details during game. I let IC events to create and shape my role. Usually I start to understand a personality of my char at 30s ranks. Then I start to write role, RP and so on. At this time you can PK, you may have some friends and enemies, so life is not leveling only at this point, but many fun things as well.

If you have been beated by someone who has better gear or skill, dont be dissapointed. Hunt in groups with good leader. Yes, ganking is bad, but many times its the only way for semi newbies, like we are

Success in fun:
you should pick your class/race keeping in mind OOC goals you wish to achieve, what makes fun for you: explore alone and many RP - try Herald? many fights and help others? Bard/paladin/healer in Fortress. Study a thief's system, and unusual PK style alone? Try thief binder/trapper