Anki Pro has a vast library where users share their decks. If you're studying a popular subject, try searching for it in the library using relevant keywords. You may stumble upon a deck that saves you precious time.
You have the option to preview pre-made decks before adding them to your library.
On the deck's page you will see a lot of useful information that will help you figure if the deck is exactly what you need:
Deck's name and creator, its Rating and the number of studiers
Preview of all cards inside the deck
Deck's description
A field where you can also rate the deck after you've studied it
Once you've found a suitable deck, simply click “Duplicate deck” and return to the home page “My Decks” to start learning.
Typically, if a pre-made deck isn't full and hasn't reached the 3000 flashcards limit, you can add your own cards to it. However, if the deck has already reached its capacity, you won't be able to add additional cards. Moreover, feel free to delete any pre-made flashcards from these decks if they don't align with your learning objectives or if you wish to make room for your own cards.