It depends on your village level on what card you can find. It also depends on if the card is rare or not. Usually the more chests you buy the more cards you will find in your specific village level. Make sure not to leave any cards behind and to collect as many as possible. If you complete card collections you will receive rewards. Also you should know you will only find gold cards in higher level villages.
If you can’t find any new card in your village its a good sign to move up to the next village. Also you should keep in mind not every player is finding the same cards in the exact same place. The cards can be found anywhere throughout your village.
Here is a complete card list, which gets updated weekly.