Student looking for a backup card (since Discover isn’t accepted everywhere)

I currently have a discover it secured card, and I keep almost all of my money in a HYSA. However, I’m concerned about what might happen if I’m ever somewhere that doesn’t take discover, especially in an emergency, and so I’m considering getting a visa/mastercard credit card to use as a backup. The reason I want a credit card rather is so I can keep my money in the HYSA.

Is this a good idea? And if so, what would be some good no fee cards to look in to?