Nerdwallet.com and thepointsguy.com are good places to start, to see what's out there.
If you treat your credit cards as if they were debit cards, there's only upside and you can get a lot of free stuff. Personally I have a Chase Sapphire Reserve (effectively 4.5% back on dining and travel expenses), an Amazon credit card (3% back from Amazon), a Discover card (rotating 5% cash back categories ranging from gas to groceries to restaurants), and Citi Double Cash (effectively 2% on everything, which I use for expenses that don't fall under any of the above).
So for anything I buy, I'm never getting less than 2% back in rewards. It adds up really quickly!