What other type of mushroom can I use if I can’t find cremini at the store?

Baby bellas.

Hi Cynthia! I find Portobello mushroom to be a great substitute for Cremini (also called Baby Bella), since it's essentially a more grown-up version of it. And if not, you couldn't go wrong with Shiitake, either, for a nice meaty depth. Enjoy!

Button mushrooms will work fine. Alternatively, you could cut up Portobellos, which are just big cremini mushrooms. (Both of those are marketing terms for the same type of mushroom in different sizes.)