Liest sich erstmal nicht schlecht. Hier und da ist jedoch die Zeitform falsch, weil du die Gegenwart benutzt, während du von der Vergangenheit berichtest. Und die Satzstellung ist mitunter nicht ganz sauber. Dafür ist die Rechschreibung fehlerfrei =) Besser wäre der Text so:
First day in school ever
When I remenber to my first day at school, I get nervous, becaus I did not knew, what I was doing there. I do not remember every single situation or detail but I never forget the feeling when I stepped in my class. I saw the teacher Ms.Eve and probably my future friends.It was September when I entered the building for the first time. The school building looked quite modern. It was very easy to find the way to my classroom, because my mother knew the way.
First I thought it would be great but I did not knew what was waiting for me next few years.
I also remember that it was very rainy and cold outside.
The students in class talked to each other and became friends but I was
very shy and unsure so I just sat there and hoped that somebody would do
the first step and talk to me.
In conclusiuon I can say , it was not a good first school day. By the end of the day I felt terrible and unhappy walked out of the building.
Ich hab die Änderungen in kursiv geschrieben.
Abschließend: Schau dir vor allem die Grammatik und ein wenig das Vokabular nochmal an, deine Benutzung von "rather" war so nicht ganz richtig. Außerdem erscheint es in der Prüfung besser, wenn du anstatt zweimal rather einmal ein anderes Wort verwendest, ähnlich wie ich oben.
Viel Glück bei deiner Prüfung!