Does the Retainer card grant $2 on the first Upkeep phase?
It means you merely skip the roll (you do not skip all upkeep instructions)

"It's like a salary. You usually get them through encounters. Darrell Simmons and Rita Young also start with one."

https://boardgamegeek.com/thread/397466/retainers

"If you have a copy of a "special" card, i.e. Retainer, Blessing, or Curse, and you receive another one, it replaces the first copy. This effectively means you will not roll during the next Upkeep to see if you lose the new copy (the old copy has already been replaced and lost)."

https://community.fantasyflightgames.com/topic/50931-two-retainers/