Funny experience

I heard a strong loud noise. When I oppened opened the door, I could see a music group at in my garden. In During that week, I had been having a bad days time and I was very sad and nervous. This way For this reason, my boyfriend had decided to organize organised a sorprised surprise for me and he thought this would calm me. so he thought that way, I could be more calm. When the group finished their concert, I called my boyfriend and I told him that I was very surprised and interested in happy about that his present. for me. Later, I called my family and I told their them that my boyfriend had send sent a music group for to me, and a few minutes later, they were in my house. The next Next morning I couldn't believe it. That was a beautiful and funny experience for me.

A Fun Experience (puede ser funny, pero creo que estás pensando en divertido aquí por la historia)

I heard a loud noise. When I oppened the door, I could see a music group (yo hubiera dicho band) in my garden. In That week, I had several bad days and I was very sad and nervous (restless). This way So, my boyfriend had decided to organised a surprise for me because he thought that way, I would be more calm. When the group finished their concert, I called my boyfriend and I told him that I was very surprised and interested in his present for me. Later, I called my family and I told them that my boyfriend had sent a music group for me.   A few minutes later, they were in my house.  The next morning I couldn't believe it. That was a beautiful and funny experience for me.

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In addition to the above grammar corrections, here is a more colloquial version of your story in my own words that I hope you'll find useful.

A Fun Experience

One week I was having a really hard time, so I was sad and restless.  Then, to my surprise, I heard a loud noise at the door, and when I opened it, I saw a band in my garden!  My boyfriend had decided to organize a surprise for me because he thought it would calm me down.   He was right!  When the group finished playing, I called him and told him that I really appreciated his present.  Then I called my family and told them what my boyfriend had done for me.  A few minutes later, they came over. The next morning I still couldn't believe it.  It was a beautiful and fun experience for me.