One of my favorite hobbies

I love the musical theater; it is one of my favorite hobbies.
It all started in high school, when I decided to sign up for the school theater production. In the beginning I just knew a little about this group. Everybody told me that their plays were great, but if I decided to belong to this group I would have to spend a lot of time working there. I thought about it for a couple of days and then signed me up.

 Probably It was probably one of the best experiences along of my life. This group had everything that I needed at that time. The people there shared their knowledge and worked together as a team to reach a common goal. There I met a lot of friends there, but in the beginning it was difficult at first because I was at least five years younger than everyone else. Everyone saw me as a child and certainly a child I certainly was it. I was 15. but, They changed their minds about me when they saw how enthusiastic I was and how much effort I put into the project, though. Even though I was young, they realized I still had a lot to offer.

I'm sure that you are wondering what was my job was. I built sets in this theater. Those sets were made of wood, steel, iron, etc. There was another activity something else that I had to do did: when we finished the sets, I had to move moved some of them the sets during the play.

The schedule of this activity was hectic but I didn't mind that because I enjoyed every minute of it. We spent 19 hours Between Friday and Saturday, we spent 19 hours building sets.

And to conclude I would like to say that I didn't earn any money doing this. What I gained was far more valuable: friends, knowledges, the ability to work as part of a team, and to be proud of myself for doing a good job. Currently It is difficult now to find many places where you can learn so many things.

One of my favorite hobbies

I love the musical theater and it is one of my favorite hobbies.
Everything started began for me in  at high school when I decided to sign up for the school's theatre production. in the theater of the school. At the beginning I just only knew a little of few people in this group. Everyone told me that their plays were great but if I decided to belong to this group I would end up spending a lot of time working there. I thought about it for a couple of days and then decided to sign signed me up.
Probably It was probably one of the best experiences along of my life. This group had everything that I needed in at that time, The people shared their knowledge and worked together like as a team to reach the same a common goal. There I met a lot friends there but at the begining it was found it difficult at first because I was much younger than the others by at least 5 years. Everyone saw me like as a child and at 15 years old I certainly I was it. Although I was only 15 but my enthusiams and efforts they changed soon caused them to change their minds about me. They realized that I was young but I could offer them other things.
I think that you are wondering what was my job was? I built the sets in this theater Those sets that were made of wood, steel, Iron, etc. Another activity that I had to attend do was, when we finished the sets i had to move the sets eme of them during the play.
The tight schedule of the theatre was difficult of this activity was hard but I didn't mind that because I enjoyed each every minute doing of it. We spent 19 hours working to build the sets between Friday to and Saturday. in this activity.
And to finish To conclude, I  would just like to say that I didn't earn any money with from this activity. I earned aquired more important things such as making new than that like friends, knowledges, learning new skills and how to work as a member of a team , knowing to team up and to be proud of myself for doing a good job. Currently It is difficult now to find many places where you can learn so many things.

One of my favorite hobbies

I love the musical theater and it is one of my favorite hobbies. 
Everything started began for me in high school when I decided to sign up in for the school's theater production. of the school. At the beginning I just only knew a little of few people of this group. Everyone told me that their plays were great but If I decided to belong to this group I would end up spending a lot of time working there. I thought about it for a couple of days and then decided to signed me up. 
Probably It was probably one of the best experiences along of my life. This group had everything that I (make sure that you always use a capital letter be begin a name, place or language)  needed in at that time, The people shared their knowledge and worked together like a team to reach the same a common (this is just a better way of saying the same thing) goal. There I met a lot of new friends there but found it difficult at first at the begining it was dificult because I was younger than all of the others by at least 5 years. Everyone (again it means the same as "everybody" but just sounds better in this context)  saw me like as a child and at 15 years old I certainly I was it. I was 15 but with my enthusiasms and efforts they soon changed their minds about me. They realized that although I was young but I could offer other things. 
I think that you are wondering, what was my job was?(only use a capital letter at the beginning of a new sentence)  I built the sets in for this theater. Those sets were made of wood, steel, iron, etc. Another activity that I had to attend was, when we finished the sets i had to move some of them the sets during the play. 
The schedule lack of time that I had to do ofthis activity job was hard but I didn't mind that didn't bother me because I enjoyed each every minute doing it. We spent 19 hours doing this working to build the sets between Friday to and Saturday. in this activity. 

And (remember to never begin a sentence with "and" or "but") To finish conclude, I would just like to say that I didn't earn any money with from this activity. I earned gained more important things than that like such as making new friends, knowledges,learning new skills, knowing how to work with a group of people team up and being proud of myself for doing a good job. Currently It is difficult now to find many places where you can learn so many things.

Good job! Although the meaning of your post was clear it needed some rewording and rearrangement to make it sound just right.  Remember to always capitalize "I".

I love musical theatre also although I don't have the skills to either act or build sets.  I am only good at watching them!