HTTPS security (NodeMCU ESP32)?

I am using the NodeMCU ESP32 and after a bit of research I find out that I don’t really need the Certificate of the SSL site or the fingerprint when connecting using HTTPS, but it is stated that this is less secure if I don’t! I’m only posting a few numbers in the URL and sending to my encrypted website! I have no working code yet, but how is it less secure if I don’t use Cert/SHA fingerprint? I mean how would my own website be “insecure” to connect to in any way shape or form?

And will the URL request also be encrypted or only the page?

I don’t want people to be able to sniff my URL info if it’s possible to prevent it!

But I also don’t wanna have to come in to my code and change the certificate every time it runs out!