Fresh 80 Gearing Help

As a fresh 80 on Frostmourne...I am not sure what my next step is. I can't queue for Heroic Dungeons as my gear score is too low. I was told to farm the 4 factions to be able to purchase lvl 200 gear from the vendors. I have started doing this but just wanted to make sure I wasn't missing anything else. I equipped the tabard for Ebon Blade then did a random dungeon and got no rep for the mobs, not sure if that was a glitch. As a Warlock queueing as DPS can take a while and the fact that no rep was given in the dungeon made me a little sad.

Is grinding honor and buying pvp gear a solution? I know it's not great for dungeons but I think it could trick the system into letting me queue for heroic.

Lastly, somebody mentioned to me about wintergrasp mini raid/dungeon for gear?

Thanks!

Buy AH blues if you can, grind rep for blues from faction QM's, run some specific dungeons (the high level ones, UP, Occulus, HoL, CoS and the like) to get some gear, and once you have around 2.2k gs look for people trying to do walk in heroic dungeons. This means instead of using HRDF, you just walk to the dungeon and go in on heroic. You don't get the EoH for finishing the dungeon, but I mean realistically RDF shouldn't even be activated yet so it's not a huge deal. You'll slowly start getting gear and reach 190 average ilvl and can queue for HRDF

You can also buy some items in the warmane store! Worked for me :)

As ret paladin what faction repus should I grind first?

You can actually go to Heroic Dungeons, you just can't use the Random finder tool, just create a 5 man group and go on foot :)