The action represented by V2 occurs before the action represented by V1 takes place.
前 indicates temporal relationship between the two actions. Note that V1 is in the dictionary form (V dic.). Action nouns (VN) such as りょこう (trip) and しょくじ (meal) can be used instead of V1. In such cases, VN modifies the following noun 前; therefore, の must be used between them.
父は いつも ねる前に、おふろに 入ります。
My father always takes a bath before he goes to bed.
マナさんは 日本へ 来る前に、日本ごを べんきょうしました。
Mana studied Japanese before coming to Japan.
マナさんは りょこうの 前に、とけいを かいました。
Mana bought a watch/clock before the trip.
しょくじの 前に、手を あらって ください。
Please wash your hands before meals.
Lesson 6-1-2「家の 前に びょういんが あります。」
There is a hospital in front of my house.