Well number one...has the LORD called you to take this position? I talked about this is a previous post about accepting positions because there is a need, is not a good thing. You accept a position if the LORD has called you and appointed you to take this position.
That's the first question you must sincerely ask and answer to God and yourself. If it is "NO,God has not told me to take this position." Then you must immediately draw back and speak with whomever is your Overseer and tell them the truth. That you took the position out of haste or lack thereof.
If God told you take this position, man....I would say how rough it was for me to training my ear! But it was so much easier than I thought it was. Sometimes playing is more difficult than hearing and teaching parts....well, I agree to that fully.
Well, you must find that person who is steping down to give you some BASICS...teaching parts, dress codes, defaults, systematic issues etc...and of course ask the Holy Spirit to help you understand and get these basic things, which is your foundation. AND YOU MUST BE SURE THAT YOUR FOUNDATION IS STURDY AND SURE.
I hope I've helped in some way.
Any other questions?