I would do some checking in your area as it all will depend on what your local market will bear. Some folks here, for example, charge $50 per night and some $100 per night, so there is a huge discrepancy. I would look for local pet sitting pricing and then perhaps come up with a price in the middle. When you are younger, that might be a good thing to start out with - and then as you gain more experience and get good reviews from your customers, you can increase your rates accordingly. You always have to know what the base rate of pay is for your task though in your particular geographic area and then go from there.