prosze o sprawdzenie, pilne ;)

My 15 birthday was really unusual and unforgettable, because I was spending this day far from my home. In this time I was in Latria, because I was taking part in student change.
So we started celebrating at half pas tto first. My friends sang “happy birthday” very loudly and they woke up girls in next room. In the morning my friend told everybody, that is my celebration. Next we went to school, when we must was doing the project with our friend in students change. I went with my friend in Latvia to her home. But I was in Katia’s home very briefly because I went to the shopping with my friend in Poland. When we backed to hostel we were eating supper and we went to beach. We were wandering and we were looking for amber, but we can’t found something. We was backing to hostel and we were singing.
We went to sleep late, but I know that was my the strangest birthday.

Bardzo proszę o sprawdzenie, z góry dziękuję ;)

My 15 birthday was really unusual and unforgettable, because I 'was
spending' SPENT this day far from my home. 'In' AT this time I was in LatVia, because I was taking part in student EXchange.
So we started celebrating at half pasT TWO first. My friends sang
“Happy Birthday" very loudly 'and' (moze lepiej..so that) they woke up THE girls in THE next room. In the morning my friend told everybody, that IT WAS 'is' my celebration.
Next we went to school, wheRE we 'must was doing' HAD TO DO the project with our
friend 'in' FROM THE students EXchange.
But I was in Katia's home very briefly because I went 'to the' (niepotr) shopping with my friend 'in' (in czy FROM?) Poland. When we 'backed' RETURNED to THE hostel we 'were eating' ATE supper and we went to THE beach. We were wandering and we were looking for amber, but we 'can't found' COULDN'T FIND 'something' ANYTHING. 'We was' (NIGDY *we was, we to l. mnoga, a 'was' to l. poj) 'backing' (wystarczy 'we') RETURNED to THE hostel and we were singing.
We went to sleep late, but I know that THIS was 'my the' (albo jedno albo drugie) strangest birthday.

dziękuję ;)