The correct answer to this open question is the following.
The intended consequences decision was the following.
I was very aware that if I committed myself to study and work hard, I had a real chance to overcome my bad situation in school, and I could change the wrong perception my teachers had about my behavior. I knew I had to show a totally different picture of me and my work, as the kind of attitude I show at the beginning of the semester.
The decision I made that had unintended consequences was when I decided to work last summer in a fitness club as a clerk, just to make a few extra dollars and not stay at home being lazy. The unindented consequence was that the company was in the marketing and promotion period and they thought that I could be part of the marketing and advertising campaign, participation in some of the promotional videos. Just by working there and being a dedicated employee, they invited me to do some advertising and I ended up earning some more money that I invested to pay school.