前（まえ）に is used when describing something that is either ‘before something’ (in time), or ‘in front of something’ (a location). It is used with verbs (in their non-past form), or nouns. When used with nouns,
の is required before
前（まえ）に.
-
病院（びょういん）の前（まえ）にあるコンビニ。
A convenience store in front of the hospital.
-
家（いえ）に入（はい）る前（まえ）に靴（くつ）を脱（ぬ）ぐ。
I take off my shoes before I enter the house.
Another similar construction to
前（まえ）に is 手前（てまえ）
に.
前（まえ）に can be used for something that is in front of any location. However, 手前（てまえ）
に may only be used when things in front of you (or someone/something else) are being described physically.
-
銀行（ぎんこう）の前（まえ）にあるラーメン屋（や）。
The ramen shop in front of the bank.
-
私（わたし）の手前（てまえ）にある着物（きもの）は高（たか）いです。
The kimono right in front of me is expensive.