I don't understand. This game is more difficult for me than any other. :o
What do the Quarry, Pit, and (I think) Dungeon give? And also, what about beasts, bricks, and gems? And why does the computer have more powerful cards than I do?

All resources in the game are equal, and all resources are needed to play cards.

In the lower right corner of each card, there is a number in a circle - this number is the amount of resource needed to play that card. And which resource is required is determined by the color of the card - whatever color it is, that resource is used for it.

It should also be distinguished:
beasts - from - the Beast Pit
bricks - from - the Quarry
gems - from - Magic
Which are respectively:
resource - its production per turn

And why does the computer have more powerful cards than I do?

You are mistaken, the cards are dealt completely randomly. And the AI in the game is generally weak.
You can also adjust the starting and winning conditions in the settings (options). If you set the initial resource production to zero, then the AI will be in a difficult situation - this is a challenging situation for it - here, indeed, the one who is lucky will win :)