Are you searching for a job?

Very Good :) There are only a few mistakes I found.

Your Post:

"The first and only job I have had was to clean in a school. I actually knowed some people in it and they said me that they were looking for someone during 2 weeks. I said I could to it and I have been choosen, this is how I got my very first job. I was very happy!"

My corrections:

"The first and only job I have had was cleaning a school. I actually knew some people there and they told me that they were looking for someone for 2 weeks. I said I could do it and I was chosen. This is how I got my very first job. I was very happy!"

Explanations:

"The first and only job I have had was cleaning a school. Here you want to use what is called the gerund form of the verb.

"I actually knew some people there and they told me that they were looking for someone for 2 weeks. Don't forget that to "know" is an irregular verb, so its past tense is "knew". Also, instead of using "say", you want to use "tell". We usually use "say' when we are quoting someone.

"I said I could do it and I was chosen. This is how I got my very first job. I was very happy!"