So it's my first character back, decided not to use my 90 and what ever. SO I made a pandaren Monk, so far am level 42 (windwalker if that matters) Joined a nice guild they gave me 5k gold to buy the 3 BoAs, all I have done is 15-42 dungeons. And Darkmoon Faire Quests to get tickets to potentially buy more BoAs later. My question is, should I just keep dunging? Or Like go somewhere and quest? I just dont know what to do...

I need help!

There really isn't a whole lot of variance. If you are able to queue quickly then run dungeons, otherwise quest in the appropriate areas. You could also have a guild mate or friend run you through the dungeons, reset when completed and do them over and over again.
Again it boils down to personal preference though so it really just depends on your play style or what you want to do.

this pretty much, if you find dungeons interesting keep running them, although your que times might fuck you up since you're dps
you should do quests while qued in dungeons

tank

Go brewmaster, tank dungeons until 90, then start WOD chain and continue questing. Youll reach 100 in no time!

if you are a tank/healer dungeons are better imo especially with the completion bonus xp

ya go heals.. seems they always have instant ques and unless you have a bad tank you barely need to do anything at all at low levels.
might get boring but I like watching movies as I level like that.. haha

Tank or heal dungeons. Did 1-90 in 4 days with just casual playing.

I'd tank over heals only if you have the boas for it. Reason is that you can most likely live longer and burst dps harder then playing healer with a bad tank.

But All my gear is for wind walker? Will it matter that much switching to tank or healer?