There are 34 Sorceries in the game:

26 that can be bought from NPCs
4 that are found in static locations
3 that are made by transposing boss souls with Ludleth of Courland in Firelink Shrine
1 that is a covenant reward (Great Deep Soul from Aldritch Faithful)

This achievement can be earned in your first playthrough or across multiple playthroughs. There are missable Sorceries tied to Orbeck of Vinheim and Anri of Astora, so be careful with their progression.

Relevant NPC and Scroll information can be found at the end of the solution.