No-one is going to be able to give you an 'accurate' idea . There are too many variable factors, location, type of property, price, reviews, quality of hosting etc. It also depends on how well you proactively market your property.
What you can do is contact your local tourism people find out about what sort of people visit the area you are interested in, footfall, capacity etc.
You can also look at existing listings similar in profile to the ones you want to buy and look at their occupany.