Centos Instance: Root & Centos user password

I launched a CentOS 7 1901-01 Lightsail instance and I am wondering about a few things.

If I try to use su - to become the root user, it asks me for my password (for the default Centos user).
I don't know what that password is. Is there one actually?

Second, is the root user enabled and does it have a password? Do I really need to use it, as I can always use the sudo?

Creating a new user for me from scratch - adding it to the wheel group - and stop using or removing the default Centos user, would that make sense?