When the clock rang, I waoked up.

I hate wakeing up early.

I went to my school withon my motorcycle.

I had a very fast motorcycle.

How did I buy that motorcycle when I was only 18 years old?

could also say "only 18?"

Those days, mMy mother promised me she would.

I passed a/the university exam and she bought a motorcycle.

say "a" if it was a regular exam for a class or something
say "the" if it was a specific exam that would be called "the university exam" - like the exam to get into the university

My motorcycle's name is Honda CBR 600RR.

There was a breakfast restaurant opposite my school.

The first day at university in Turkiye, the teachers don’t teach.

Students take care of paper works.

I went to orientation meeting.

Some students looked nervous and some students looked happy like me.

Day off, letLet's be honest, which one of us married withe first looked girlgirl they saw at university?

I'm not sure what you mean by "day off." It might be something not translatable directly from your language to English.

When the clock rang, I waoked up.

I hate wakeing up early.

I went to my school withon my motorcycle.

How did I buy that motorcycle when I was only 18 years old?

Those daysBack then, my mother had promised me that she would buy me a motorcycle if I passed my university exam.

(Combined it with the below sentence.)

My motocycle name isis the Honda CBR 600RR.

TOne the first day at university in Turkiye, teachers don’t teach.

Students take care of paperadministrative works.

I went to an orientation meeting.

Some students looked nervous and some students looked happy like me.