You don't need to do anything about the fonts if you didn't added it manually to your site like we did. Also it looks like our Ocean template is using custom font.

Are you logged in on both devices ? since it's significant difference, when you are logged-in much more things are loaded additionally. Also many phones have retina screens, so some images maybe up to 4 times larger on retina screens and load slower. Also phones usually have slower network connection. Also phones maybe less powerful than PCs. Also when you tap on links on mobiles there is usually some delay, before link start to load. So there are many factors.