VirtualBox Guest VM sizing


I have built VM using virtual box for education purposes. ansible is installed on an Oracle Enterprise Linux 7.8, My intention was to first manually deploy Oracle using Oracle Universal Installer and then using the response files build a playbook for ansible deployment of Oracle Database.
What I find is whatever I do with guest window size the Java oracle installer screen cannot fit in the guest window. The linux guest does not use up the whole vm window. Even when I stretch the VM the actual size remains the same - I have tried all the options under view etc
appreciate some help as I intend to install docker etc too and try various options.