For someone starting out, I would suggest writing about things you know about, life experiences, things you are interested in and things you believe others would be interested in as well. Informative educational and entertaining or how to hubs are very popular. It helps to use pictures and videos if possible.
If you click the help button up at the top right-hand corner of the HubPages screens, it will give you all kinds of tips and advice on just about everything you need to know about HubPages. Good luck and welcome. I hope to be hearing more from you.