World of Warcraft has undergone a few talent changes over the years, and the system we see in classic is very different from what we see in the Shadowlands.
On top of talents, in the Shadowlands we have a similar system know as "soulbinds" that use conduits collected throughout the world that increase player power.
Read more: WoW Shadowlands How To Get Conduits.
WoW Shadowlands: How to Change Talents
To change your basic class talents, there are few ways to do this, First, you can freely change these at any "rested" location.
Rested locations are counted as any major city or building that has an innkeeper. If you are preparing to do a dungeon or raid you are likely to be in a major city already, so check your talents are correct before you head out.
Next, Inscription players can create and sell an item called Tome of the Still Mind. Be careful when buying these as there are many different types of tomes for different expansions and they all are level restricted.
Codex of the Still Mind is another inscription item that can be created by players, and once placed on the ground it allows all party and raid members to change their talents. This item is primarily used by raiding guilds.
These items can also be used to change between soulbinds and the path each one individually takes, however, if you wish to change the conduits inside of them you must return to your Forge of Bonds in your covenant hall.