In Mymag you can manage fonts and their properties. The theme comes with two preset default Google Fonts: Open Sans and Roboto, (Roboto using for the menu, post titles, blocks title, etc. Open Sans using for body, paragraph tags).
Go to Appearance → Theme Options → Typography
In Typography Settings tab, Select the section where you want to apply the Google fonts. Google Fonts are included in the font-family drop-down list, For each section you can use a different type of Google Fonts.
If you want to specify what type of character subset to load (by default is “Latin”), you can select Fonts Settings tab then select from Character sets what character subsets will be loaded for each google font. If you choose only the character subset that you need, you will help prevent slowness on your webpage.
You can choose the font weight you want for your fonts from the Font Weight found in Fonts Setting tab.
The fonts will load with the default font weight of 400 and will load extra weights when the following selectors are enabled.
Note: The font you choose must have the font-weight available otherwise the font weight will not work. You will need to access the Google font repository and check if the font includes the font-weight you want to use.