Next thing to do was to create a database with dbca. You need to be user oracle when running dbca.
It is located in the same directory /u01/app/oracle/product/11.2.0/dbhome_1/bin
Some of the key parts in installation is to set up the password for the created admin users like sys, sysman etc. I would strongly recommend to set the same password for all at least for test environments.
I selected to set the DB data to a different volume that I have mounted to /u02
I also selected no flash recovery area, which in general is a bad idea, but for a small internal test machine it saves disk. Also no archiving, which is not good for production but ok for own small test environment
I also installed the sample schemas as several Oracle tutorials use them
My virtual image has 7G of memory and I set about 1G for the DB as there will be no real use for it; your mileage may vary.
I also selected AL32UTF8 for the character set.
And now we have DB created.