What is the process of filing a civil compromise in AZ state

fraud or forgery: I received two checks in the mail from an organization that I am a member of they came made out to me one was 180.00 and 190.00 I cashed one that evening and the following morning at a local market the next day I was told that the checks were a forgery and that they were made by someone who made them on a computer or something they did not explain to me any ways I have no Idea who sent them to me or why I did a stupid thing by cashing them but I had no Knowledge of these circumstances I need to know what it is I should do before I am arrested for this .They have told me it was a serious matter and I would like to resolve this in a thorough manner but I need to prepare myself for the arrest because it seems inevidable I need to know what are the best things I should do to aviod the worst case senerio . I can not stay in jail I have to many responsibilities and that is why I am so scared Thank you Lloyd