I need advice from independent contractors. How do I set up a contract for company that wants me to be on call

The company wants ten days of call per month. I also want the option to set up their medical equipment on days that I am not on call. I want to set a fee for each appointment. I of course will be stuck paying for gas expenses so I need some leeway. Currently I am getting just 2500.00 per month from this company. He wants to use me with unlimited setups and unlimited time and travel in the suburbs of Chicago.I need advice from independent contractors. How do I set up a contract for company that wants me to be on call
Just print everything out clearly. For instance, I agree to work for ABC Co. for $2500 a month and that will include and then list what it includes. If it includes the 10 days you are on call then write that in. If you are charging extra for the 10 days on call then write that out separately. Also, list which 10 days as specifically as possible. If you are charging extra to set up their medical equipment then include that with the fees. Anything you are charging for you need to itemize and list the fees. I don't think I would agree to unlimited setups, time %26amp; travel for the $2500 because you might get stuck doing something every day and spending more than that. Have the $2500 cover so many set ups and so many trips, etc. and then have a charge for each set up after that. Like the $2500 covers 10 setups and then there's a fee for of $200 for each one after that. I have no idea how much you charge for what you do so I'm just throwing numbers around. Just be specific so if you ever have to go to court, you'll have everything in writing.