Elden Ring PC | Sorceress Sellen full dialogue first encounter & initial sorceries inventory

Sorceress Sellen
"Sorceress Sellen is a Merchant and NPC in Elden Ring. She can be found inside the Waypoint Ruins, far east from where you first arrive in Limgrave. She can teach you Sorceries. She can also be made available as an NPC Summon for specific battles."
https://eldenring.wiki.fextralife.com/Sorceress+Sellen

Initial inventory:
Glintstone Pebble
Glintstone Stars
Glintstone Arc
Crystal Barrage
Scholar's Armament
Scholar's Shield

There are steps you can take to unlock more sorceries in her inventory. The Fextralife article above goes over it.