Hi Small Rider,

Don't worry, we've all started somewhere and we've all learned to use OSM. Your help editing Tanger is extremely valuable.

As per the roundabout and the bus relations, I'll explain it to you.

When editing such a roundabout, it's tricky because you have to watch out for bus routes which go through it. First, you delete the roundabout from its relations in order to draw a new roundabout. Next, you have to "split" parts of the roundabout at places where the bus route passes.

To split a way (a line), you simply click on a point, and click on "X". That will split it. You can then add the desired parts to the bus routes.

This has to be done because if you don't, you'll add the whole roundabout to the bus relation (which is what you did), but a bus doesn't go around the whole roundabout, it only goes straight or turns for example. 

I'm here if you have any questions. Welcome to OSM.