If you want to be where you’ve never been before, you must do what you’ve never done before.

Login to ubuntu from your usual administrative account which has sudo access
Make sure you have enough ram, swap space and disk space as per oracle requirements.
Install the required packages (first make sure ‘universe’ is enabled in your sources.list):

sudo apt-get install build-essential libaio rpm lesstif2-dev alien

Create the users and groups oracle needs:

sudo groupadd oinstall
sudo groupadd dba
sudo [...]