The first is a triggered ability: "When this permanent enters the battlefield, target player may search their library for a card named [name], reveal it, put it into their hand, then shuffle." (10/13/2023) The second ability represented by the "partner with [name]" keyword modifies the rules for deck construction in the Commander variant and has no function outside of that variant
Black uses the graveyard as a resource enough that exploring each time you draw a card is practically the same as drawing a card
She screams that shes replacement level, though, and I wouldnt bother with her in a Chandra deck
Regardless, this is a fun card, especially if you can pair it with some magecraft triggers
Your job is to figure out how to return the favor to the Eriette player in time, using their buffs to take out other players, then following up with some timely enchantment removal to turn your attention back to Eriette