Hello Heidi
You say you are new to hosting. I know it would be tempting to take a long term booking at this stage but as you are a new host I think it would be a better idea at this stage to take on a number of shorter bookings to give you some experience hosting. Doing shorter stays will give you experience of doing changeovers, meeting and greeting and will iron out any little issues you have with your place of your listing. Set your maximum stay to 7 days just for now and get some reviews under your belt.
I would also be very suspicious of the request you had.