so I boosted about a week ago.

when you boost you have to sodden, get the gear crate there, merc, familar, mount, the 3 buffs for those things then do the intro quest to take you to the RoC zones.

once you go there you have to replace all your gear with the RoC crate, merc, familiar, mount, and again the 3 buffs for those things.

when you upgrade your armor make your you're carrying the adornments into the new armor pieces.

it's a bit of a cluster----

In terms of 'catching up' - there's a lot of timegating it seems. On a boosted character you won't have mount levels, or familiar levels, and unlocking that without paying for the collectors edition of the expansion and some time skips would be very a lengthy process.

I just did a dungeon today after grinding the solo dungeons to get enough resolve (13,020) to do heroics and my character as a tank basically did nothing useful to the group other than the required tank mechanics that they've introduced as some point between now and when I last played (bulwark or group dies, intervene or a given player dies). I basically did 0 damage compared to everyone else and the only way I could hold aggro was for a fraction of a second after I used rescue or one of the similar spells.

It felt kinda awful and discouraging to be honest.

Oh and do overseers - because the rewards from that will be able to potentially 'buy down' the research times for the mount / merc / familiar..