学食に飽きたときは、ベルファで買うもよし、ファミレスで食べるもよし。

、、。

When you're sick of the school cafeteria, you can buy something at Belfair or eat at a family restaurant — either works.

Literal

School-cafeteria [to-に] got-tired time [topic-は], Belfair [at-で] buy [also-も] fine, family-restaurant [at-で] eat [also-も] fine.

The pattern V-dictionary form + も + よし is a slightly literary/archaic construction (よし is the archaic adjective よい) that stacks alternatives — 'V-ing is also fine.' 学食 is a clipped compound for 学生食堂 'student cafeteria,' and ファミレス for ファミリーレストラン 'family restaurant' — both characteristic Japanese abbreviation patterns. ベルファ is a proper noun (a specific shop). ~に飽きる uses に to mark the thing one is tired of.