I will like to hide some modules and menus from appearing on mobile or tablets devices

I don't want them to appear/visible when users visit my site using their mobile phone.

Please can someone help with the css code that should be typed in the module/menu suffix class field???

I think i found solution to this after hours of digging. For other who want to achieve same goal, just enter these code into the module class suffix: hidden-xs hidden-sm hidden-md

Support Classes : The solution is hidden module and position on desktop,tablets & mobile. You can add class suffix.
hidden-lg : Hidden on Large devices Desktops (=1200px)
hidden-md : Hidden on Medium devices Desktops (=922px)
hidden-sm : Hidden on Small devices Tablets (=768px)
hidden-xs : Hidden on Extra small devices Phones (<768px)

I found the above instruction in the layout1.xml in my template. You can find yours in your template section where all the css and others files are.

Goodluck.