Before as a preposition, is normally used to refer to time. For example, I must get home before nine o’ clock. However, it can refer to place or position in the following ways:
To talk about order in queues, lists, documents etc
Could you move back please? I was before/in front of you.
We use a before a consonant and an before a vowel
To mean ‘in the presence of somebody important.’
He is supposed to appear before the magistrates on Monday for negligent driving.