1.- No. This is not the normal way. You should be able to access to mysql with username root and the password you use at installation time. How did you access with the root user if the password provided during installation didn't work? Please check the following link to learn a bit more about the mysql component on Bitnami installations:
2.- If you receive a message saying that the port is taken means that there is other application (more concretely other apache web server) using that port. You could install django for example using the port 8081 and then access to your django application using the following url.
Please note that have receive a warning for the apache server (port 8080) but if you have installed other bitnami stack it is possible that you also get a similar message for the mysql server (port 3306). If you receive this last message you could use for example the port 3307 for the mysql database server.
I hope it helps,