That was a good start, you could include way to access the ui part of these rds servers or how to connect to them to view data on servers in some other blog !

Inside the children you have kept /about, in react-router-dom when you keep / at the start of a path, you make it absolute and absolute paths cannot be used inside the children itself, right now it will work, but if for going to MainLayout the path was /main then to goto about page the path would need to be /main/about which will fail in your case, because you are placing an absolute path as a children, FIX: remove / from the children path and for Home, you can use index: true instead of assigning it a path, keep coding !

I find CSS to be the irritating part

All the best !

That was a lot of information, it's great.

The example was a good one.