URGENT- a short paragraph on " extracurricular activities" please help me

hi all

this is my first topic on this lovely forum and i hope u would help me out with this,...

this is a paragraph i wrote answering a question about my extracurricular activities

I enjoy participating in extracuricular activities as they allow me the chance to play a role in my community and school.
there were times when i participated in summer camps, and times when i looked for work,for example, in summer 2004 and 2005 i enjoyed helping at a printing house, in 2007 i joined a peace group urging for peace, and to stop all violent acts. At school i took part in some of the activities that were held, i played for my school's soccer team, i also participated in school marathons and won a medal. Moreover i was a member of a school's student committee, we used to arrange educational competitions between schools, and organize lectures in different schools. For example, we once asked my friend's father to give a lecture on how a heart works. We also managed to have meaningful lectures on smoking and drugs, lectures that not only physicians participated in, but also people who used to do drugs and then were remorseful.

please help me if there are any mistakes that i should fix ...

Thanks in advance