External User Management Software

Good evening,

The users of my NC are primarily not online users but members of an association. For the administration of the members of this association, a book was kept very early, then an Excel spreadsheet. Actually, I was hoping that the administration could now launch via NC, but the possibilities are simply lacking.
Above all, we need more fields (entry date, position in the club, still active or already left, etc.).
After a bit of searching, I found out that NC can also be reached with users and groups via an external SQL table.
Since then I am completely free to choose the member management software, the main thing is that it saves in mySQL.

Can someone recommend something specific to me?
Gladly also with the possibility to create maillinglists.
Or can you give me specific keywords as such software could be called.

It is only important that it is capable of running on normal web space, ie PHP js and HTML.

Thanks and regards