Just play it.
Try it, level to lvl20 and see if it fits for you
About "how long to lv60".
I needed exactly 8 Days /played.
But: I was farming the whole last AV weekend rep when I had time to play. Unfortunately just got to 8/12k honored.
So if you just stick to leveling it should be 6-7 days I think. As you never played Vanilla, it could be about 8-10 Days. Note: I am talking about /played time not your "real life sleeping days"
But take also in account, that some classes level easier and some classes just suck at it, like my warrior ^^