Ambitions as a Spanish Teacher

I've been wondering what kind of goals and aims exist in a teaching career.

"ing" was added to the end of "teach", because you "teach" is describing "career." "Teaching" is what this "career" does, and the person with this career is called a "teacher"

This aspect includes that we are part of a bad paying job, and its professionals neither are going to be rich, nor they are going to be able to amass a big fortune.

"Involves" was changed to "includes", because "involves" would tell your reader that this could be a bad paying job, but you want to tell your reader that this is a bad paying job, so you should use "includes."

"in front" was changed to "part," because "in front" is phrase that tells your reader he or she could probably face this problem if he or she becomes a teacher, but you want your reader to know, this is what he or she WILL face if he or she becomes a teacher.

Paid was changed to paying, because paid is a word to say it happened in the past, but you want to say it is still happening now, so paying is the proper word to use here.

never was removed because in English, you cannot have two negative words together.

Commas were added in some places to add a pause. Imagine that you or your reader is speaking these words. The commas tell your reader that these sentences are not supposed to be read quickly, but slowly, so they can carefully read the information.
Read the corrected sentence, and your original sentence, then think of which sounds more natural when spoken.

The real ambition and motivation to work as a language teacher, is being aware of improving the intellectual life of the others.

"you are" was removed, because the reader can understand you are talking about him or her in this thought.

This work worth ___, because through your social service, you are helping other people to grow as a humans.

the blank line was added, so you can fill it in yourself. This is because you must explain to your reader what was worth this.
Was the sacrifice of being poorly paid worth helping?
Was working long hours worth helping students?

Although this process might not seems useful, if we consider that we live in a society that expects fast outcomes, we actually have the key to access to this knowledge that can provide happiness.

not was added after might, because unuseful is not a real word. =p

"s" was added at the end of expect, because you are telling your reader that this is happening right now.
You may also say "is expecting" to say the same thing.

actually we, was swtiched to show that "we" posses "the key." This is because in this situation, you are explaining this to your reader as a surprise.
Ex. "do we have the key to hapiness?"
"we actually do!"

You are telling you reader that he or she has the key, as if he or she did not know it.
If you say "actually we," it is being used as a contradiction.
Ex. "we do not have the key to happiness"
" actually, we do!"