These words is a little hard for me

awkward=(adj) embarrassing
For example: I currently have an awkward position situation at work because of low educational background.

rapid=(adj) meaning very fast or quickly.
For example: The country's rapid economic growth in the 1980s.

approach=(noun, verb) way, another meaning is near, get close to.
For example: Therefore, this seems to be an one approach to losing weight.
If you approach more words, more benefits for study. No! what do you think 'approach' means here?

If you approach the animals quietly you can get close. 

It is approaching midnight now.

brilliant=be full of knowledge. No! For example:She has a brilliant mind. Example is ok

brilliant = striking, shining, or talented.

She had a 'brilliant career' , 'his concert was a brilliant success.'

These words are (is) a little hard for me      (you need to use 'are' because you talked about more than one word. If just one word was hard for you, then, yes, you could say 'this word is...')

awkward=embarrassing
For example: I currently have an awkward position at work because of low education background.  (educationg backgroud).  A better example would be if a girl met her boyfriend's ex-girlfriend 'It was an awkward/embarrassing moment when I met her'.

 
rapid=means (meas) very fast (fastj) or quickly.
For example:The country's rapid economic growth in the 1980s.

approach=way,another meaning is near,get close to.
For example:Therefore,this seems to be a (an) good approach to lose weight.
If you approach more words, more benifits for study. - this sentence is not used in English. I think you mean if you learn more words it will benefit your studies. However, approach is not the word to use.   For approach you could say: 'As the train approached the station, people were waiting to get on'  

brilliant=be full of knowledge.
For example:She has a brilliant mind.