over

We're going to go to the bridge over the River Kwai.

To go 'over' something means to pass above it.  In this case the bridge is used to pass above water. Notice the following:

1. We live next to the airport, so planes fly over all the time.
   
2. Do you think you can climb over that fence?
   

got trained

I got trained in scuba diving in Thailand in Ko Tao.

When we 'get trained' to do something we learn how to do a specific task. Notice the following:

1. He had to get trained in first aid to work here.
   
2. You will get trained during the first week that you work here.
   

pretty cheap

Scuba diving is pretty cheap in Thailand.

If something is 'pretty cheap' it is not expensive. It costs a little money, but not a lot. Notice the following:

1. This restaurant has really good food and it's pretty cheap/
   
2. It's pretty cheap to travel here, but not as cheap as in Vietnam.
   

good friends

Adrienne and I are good friends.

A 'good friend' is somebody that you are emotionally close to and can trust.  You know a lot about that person and she knows a lot about you. Notice the following:

1. They have been good friends their whole lives.
   
2. We were very good friends when we were younger.
   

antique

We love to go to flea markets to find used antique kimonos.

Something 'antique' was made a long time ago in the past or is not modern.  We would not use this word to describe something that was made only a few years ago. Notice the following:

1. She goes shopping for antique jewelry with her friends.
   
2. My grandparents still have an antique telephone.