Self-introduction

This is my first time to writewriting a letter inon this webwebsite.

I will go to my university inon September 15.

Or: I will start attending (my) university on September 15.

I don't have expectation forany expectations regarding my university'suniversity life, because I worry about relationshiprelationships. (??)

This is my first time to writewriting a letter inon this webwebsite.

Two small things. After "my first time," English uses the -ing form: my first time writing. And for a site we say on this website — "in this web" isn't used.

I will go to mystart university inon September 15.

With a specific date English uses on: on September 15. (in is for a month by itself — in September.) Also, for beginning your studies, start university sounds more natural than go to my university.

I don't have expectationany expectations for my university'suniversity life, because I worryI'm worried about relationshiprelationships.

A few small things. After any, English wants the plural: any expectations. University life works as a set phrase — my university's life sounds like the university itself has a life. Put a space after the comma. And for how you feel right now, I'm worried about... fits better than I worry about..., which describes a habit.

This is my first time to write writing (a letter in) on this webwebsite.

This is my first time to write a letter inwriting on this webwebsite.

I will go to my university inon September 15.

I don't have expectationany expectations for my university'suniversity life, because I worry about my relationship