Which card should I pair with my American Express Blue Cash Card?

Hello as the title states, I'm looking to optimize my benifits of using credit cards. I'm 20 and have my Orginal Capital One Credit Card:Limit-500$ and American Blue Cash Card:Limit-5,000$
I don't use my Capital One card and was looking into getting a new card for better benefits in maybe gas/groceries than my blue cash card. I soley use the blue cash card now for everything.Also should I cancel the capital one card if I get a new one?

So any ideas? I would be happy to answer questions if need be. Thanks in advance🤑