You have to be patient, sure there are some musicians who learn to play like a "beast" in a few months, but that is not a realistic goal. Go get some music lessons. Better yet, let your father teach you! I'm sure he wont charge too much money.
Also check out that dvd boneyee recomended. I have it and it, and I think will help you
PRAY! PRAY! PRAY! All summer long I had been asking God to help me with my music, and these past few months he has given me so many opportunities
Below is my story, just to show you that you have to be patient (and pray)
In Fall of 2005, A coworker said that thier church needed an organist. So I went to rehearsal and played, but they said i wasnt good enough. Fast foward to Fall 2007. I visited the chuch, just to visit. I spoke to the bass player, He said that all of the musicians were gonna be away, so he asked could I fill in, Having not heard me play since 2005. So I fill in, do a decent job and now I'm playing for them full time.
Now I'm also playing for a couple of groups, soloist and evangelist
To all those starting out in church, remember to be patient, practice and PRAY