Enrolment

Hi everyone,

I face a problem that I can't solve.

To give you a bit of context, I am an administrator on a moodle but I don't have access to the server or database. Our moodle is on version 3.5.
I was asked to create a role that gives the user the possibility to go in his/her courses but prevent said user from self-enrolling in others.
The self-enrol courses are in their own category, separated from other courses. We can't put a password on them.
So, in short I'd like to make a role that prevent users with a the role to go around our Moodle and enrol in courses they should not access

I tried the guest access but we'd like to keep logs with names.
I also tried to prevent the role from self enrolment but this capabilites seems to be available in moodle 3.10. Same for viewcourselist, available from 3.7.
I even tried, as a last resort, to hide a "list of categories" block for this role but I get an error message preventing me to do so ( https://docs.moodle.org/310/en/error/moodle/cannotoverridebaserole).

So is there a way that could allow me to do that ?
I thank you all for your time and your replies