There are plenty of good QR code generators. I use
https://www.qr-code-generator.com/
But you are right to be wary - especially when reading QR codes. Make sure that your QR code reader is one that lets you look at the URL first, not one that just loads up automatically. Then you can see that the website being loaded is the one that you are expecting. People have been known to paste fake QR codes over real ones in public places, for example.