My diary

I studied at the university 3 years ago in Málaga. I have a degree as a music teacher, but I´m not working in a public school because I need to pass the English test. ** I also have to pass an entrance exam.
Nowadays I work as a singer in a hotel at nights. ** In fact, I have to work tonight.

** = One sentence was split into two separate sentences. This was done in order to avoid a run- on sentence. A run- on sentence is when independent phrases are joined without appropriate punctuation.

Using a period (.) instead of a comma (,) will reduce the amount of information mentioned in a single sentence. Think of a period (.) like a breath of fresh air. 

My diary

I studied in the at university 3 years ago in Málaga. I have a degree in music teacher, but I'm not working in a public school as a teacher because I need to pass the English test and I also have to pass an entrance exam.

Otro manera de escribir la oración previa es 

I trained as a music teacher, but I'm not working in a public school because I need to pass the English test, and I also have to pass an entrance exam.

Nowadays I work have a job singing in a hotel at nights. In fact, I have to work tonight.