About Friday

I don't have any homework or etc. so I will write my experiences about a party on last Friday.
I don't have any homework or anything else to do, so I will write my experiences about a party last Friday.
("etc." isn't usually used in this context, but if you were to use it, you don't need to add "or")

It was Armada Night and the main music was trance.
Good

During my high school period I was listening rock and metal and I was a little bit prejudiced about electronical music.
During my high school period I was listening to rock and metal, and was a little bit prejudiced towards electronic music.
(It is more common to say "When I was in high school" rather than "During my high school period", although both ways work. "Electronical" isn't a word, so I'm not sure whether you are referring to "Electronic music" or "Electronica")

But when I started to university things started to change.
But when I started university, things started to change.

First, I listened some house songs but it was making me bored quickly.
Good

Then I started to listen Infected Mushroom and it was amazing for 6-7 months but again I got bored.
Then I started to listen to Infected Mushroom and it was amazing for 6-7 months, but again I got bored.

I think the reason I got bored quickly is not mastering about those types of music.
I think the reason I got bored quickly was because I could not master those types of music.

But one of my friend has a great knowledge about trance music and sent me some songs to listen.
But one of my friends is very knowledgeable about trance music and sent me some songs to listen to.
or
But one of my friends knows a lot about trance music and sent me some songs to listen to.

I really get excited about that music type by listening, and after that party I can say it is unbelievable! 
I get really excited when I listen to that type of music, and after that party I can say it is unbelievable!
(You don't generally start a sentence with "and", especially when it is so closely related to the last sentence, so just add it on to the last one)

The party was gorgeous. The music, people, lights, everything was perfect.
The party was gourgeous. The music, people and lights were perfect.
(The last word in a list usually has an "and" before it)

Since that day in my mind some trance songs are keep playing on.
Since that day, trance songs keep playing in my mind

I can say that trance will be my favourite and I'm sure I will listen it for a really long time!
I can say that trance will be my favourite and I'm sure that I will listen to it for a really long time!