Question about unlocking and upgrading

Hello people,
I'm enclosing an image to clarify my question (I also deselected the cards I use for the photo, I'm not going to play cards openly of course).

As you can see I reached level 15 with my assault.

I need 7 more points to unlock everything up to level 30.

In addition, I have 4 points left and the game gives me the opportunity to upgrade the cards I already have.

My question is:
Will there be cards after level 30 or can I gradually upgrade the first cards?

Thank you,
Mondriaan