Can you help me compress or gzip my pages.

Helo. I am doing this Google speed test on my pages ie: http://cateringhuset.no/produkt/bacalao/
I get a Mobile score of 48/100 and Mr Google sugest i activate compress/GZip, eliminate the blocking in Java and CSS that makes content wait for it before it loads, and adapt cache time/date.
All this is Greek to me, i try to learn from Mr Google, but i really dont understand.
Can you please tell me how to fix this?