There are two sites to track cards if you don't know:

https://arrtripletriad.com/en/cards

This one is better for the end game and easier to use due to the compact list being exactly as it is in game so it's quick to mark what you have. It also tends to update faster.

It allows you to hide all owned cards and has a deck theory crafting component which is good if you want to discuss strategies with people online.


https://ffxivtriad.com/

This one is better if you're starting out I think in regards to tracking NPCs and when their times are open for play. It also has the useful feature of marking cards with an '!' so that you can focus on specific sets of cards (like let's say you were trying to get all primal cards)

This one does will move cards owned to a collection at the top of the page but can cause longer loading times due to how the scripting is loaded. I've found sometimes information is slightly off on it. Like... Pazuzu card was released in 4.45 not 4.4 as it's written.


On an offnote

I've found that cards added to outdated content seemingly have a terrible drop rate