Sentences / Word meaning

I'm studying how to use some words in different sentences. Could you correct them?

The enliven atmosphere in the office is due to the new workmate we have ( Could you give me more examples of sentences with the word enliven?)
Her influence was a key when it came to close the deal.
Friends in the office inspire us to feel more entuthiastic about the job we do.
Happiness at work stimulates worforce.
I've met most of my friends at work
The members of the club had their encounter in Bristol Square.
I found him crying behind a tree.
I've known him since Kindergarten.

I also should know the difference between peer, colleague, companion and fellow.

Peer (sb equal) : His peers voted him best actor ( other actors voted him?)

Colleague (co-worker) : Dana is my colleague, her desk is in front of mine, she is responsible for the creative part of our project.

Companion (friend, lover, accompanying person) : David Ley has been my companion since World War II.

Fellow (of same group, co-) The fellow employees organised him a party for his 25th anniversary at the company.

Why do you use in the following sentence find and not meet?

I found John at the station waiting for a taxi.