Thanks all. It's confusing. You know you're in trouble when you're not sure where to start!
In this instance I need to create 2 quite simple static sites that might change some small amounts of content twice a year. But if I'm going to invest the time and energy learning new languages I wanted them to be the right ones for more sites in the future and maybe more complex ones.
If I go down the HMTL / CSS route for now, can I add other stuff (php / mysql etc) on later?
Thanks for your time. Maybe I should just buy a book and get on with it!!