New player needing advice on Dragon Stones

Hi, I started during the part 1 of the festival, and managed to get Broly, Beast Gohan and the Gammas.

I'm not sure of what I should do now with my Dragon Stones :

• try to get more Beast Gohan copies for its hidden potential

• try to get other featured units (especially on the Gammas banner, where I only got them)

• save