To is a preposition of direction.
When talking about the direction of a motion, to is used. ex. I like walking to the park.
To can be used to express the location of one place in reference to another place. ex. The ballpark is to the east of the department store.
To can be used to refer to how many minutes before the hour it is. ex. The movie begins at 15 to 7 (p.m.). To can be used to show that a condition is almost reached. ex. I was close to tears.
To can be used to show which person or thing is affected by an action. ex. I was mean to my sister.
To can be used to show the relationship between to people. ex. He is married to a rich woman.
To can be used to show that two things are attached. ex. The bicycle is locked to the fence.
Prepositions of direction are found just in front of the location word or phrase.
to + location word/phrase
ex. I drive to work.
Be careful because to can also be used to mark infinitives (dictionary forms of verbs).
ex. I want to eat soon.
To can also be used with ~ing forms of verbs (present participles) when they are used like nouns. ex. I look forward to hearing your story.