@Pauline
Well done.
What I have found is that if you can do the following, you are good.
- Image Compression
- minify css/js/html
- Enable Caching
- Add Expires to your content which tells the servers and browser how long the cache can live (this is a challenge for those who manage their CSS as you now cannot use the same file name to update content.)
Along with Page Speed insight which G uses to assess user experience, I have used this web site to look at all the calls
http://tools.pingdom.com/
It really shows you the calls you make with all the delays.
After everything, my conclusion is that I need to switch hosting provider if I want speed or move to better servers. Obviously, you get what you pay for …