How to price your services.
First, you need to understand your costs to operate your machine per hour. Start by figuring out your fuel cost per hour.
Next figure out your fixed costs divided by the number of hours you will likely work. With your working only weekends, optimistically, you will only work about 8 hrs/day x 8 days per month (that's if you could keep yourself booked, and had no travel time) so 64 hours/month. Your monthly fixed costs are your loan payment, insurance payments, etc. Divide this amount by 64 hours and add the fuel costs, and you'll see what you need to charge just to break even. That doesn't include any income for yourself.
We haven't figured maintainence either. You may be able to calculate the costs for required service, but I suspect with a new machine, you don't really have a feel for breakdown frequency and amounts.
Once you have an idea about what you need to make per hour to break even, then you need to compare this with the going market rate for your area. If it's $100/hour and your costs are $40, then you may be able to make this work. If the going rate is $50/hour, then all you can hope to do is offset some of your costs. You may not be able to get the prevailing rate if you don't have the experience, time to do the job immediately, insurance, transportation, etc.
The big variable is how many hours you can actually work. While it may be all rosey if you can work 64 hours, what happens when you only work 6, 10 or 20 hours per month? It will also take time and money to advertise, respond to queries, visit potential customers to provide bids and estimates. All-in-all, making money with your tractor is a lot like work!
Good luck with your venture!
