This question already has an answer here:
I want to take in a WIFI signal and provide internet service to this Ubuntu machine AND others on my hardwired ethernet connection.
I have asked this elsewhere and only got 'it's easy, use the GUI' but that was less than helpful.
Pointing me to where I can RTFM (Read The Fine Manual) is fine too, or even put the details in here somewhere!
Thanks for your support.