Complete Beginner.

I just bought the game. Very excited. It is going to be my very first Paradox grand strategy game. It is actually the first actual grand strategy game I'll play in general.

Do you think I just buy the starter pack DLC's or any other DLC that is a must have?

I am looking forward to learn the game first, then spend money on extra stuff, but I don't know if there are any must have features that comes with DLC's.