I was able to find the CalDav link in the calendar integration but I’m unsure about the username and password to use with it. Is it the same as my users? Is it possible to generate a separate password for the CalDav access
By default yes, unless unless you use 2FA which prevents it.
Yes, see the documentation :
https://docs.nextcloud.com/server/latest/user_manual/en/session_management.html#managing-devices