Please Help!

Thank you in advance :)

Sol work as an accountant (supposedly to be an assistant but I ended doing most accounting duties with no training) for a law firm - its a sole proprietorship firm. The firm been making less profit and more expenses and I was told to figure out what to cut back on. I have no idea what I need to arrived at the conclusion on what needs to be cut back on. Advertising wise - they pay A LOT for it and need my input on cancellations, changes in services, financing options, and future expenses. I have NO idea on which ads pull in more customers. What should I do and what kind of information do I need to make the decisions? PLEASE HELP! Thanks in advance