The way it works is this; you must get one character at least into the Forgotten Gods expansion content to be able to buy Merit Tokens. There’s a Champion’s Merit which will unlock Elite difficulty for other characters and a Savior’s Merit which does the same for Ultimate. You must get a character into either of these difficulties to be able to buy the relevant Token, i.e. Elite to get the Champion’s and Ultimate to get the Savior’s. You buy these Merit Tokens and then place them in the transfer stash for new characters to be able to access once they can get inside the DC prison. Or, if you have the Crucible add on, you can exit back to the character selection screen, choose the Crucible add on there, jump into the Crucible to access the smuggler there to get whichever Token you want to use from L1.
Here’ a transcript and video link where Zantai showed off how the Tokens work.
As for which builds to try next, have a look at the Beginner’s Compendium
and for pets have a look here.
While these are endgame set ups there are some links in there to budget/beginner builds you can use as well.
