SPPEDoverPOWER. First off, welcome once again.
PvE stands for Person Versus Environment. The PvP server is an open world person versus person setting with very few "safe zones" whereas the PvE Server in order to participate in PvP you'll need to turn on your characters PvP flag (optional for all characters). PvE Server is meant for people who enjoy questing and dungeons and leveling without the risk of an open world PvP (which can include ganking, level trolls, etc.)
Fighter class paths, spell list and moderate spell explanations can be found at THIS LINK
, you may wish to ask Mako, Kast, or other lvl 24/25 fighter characters more specific fighter questions as they have a very good understanding of this class. As stated above, trait paths for classes has NOT been implemented yet nor any detailed explanations given, we'll all wait for those to be revealed in the months to come.