Where are you planning to move to Italy from? Some nationalities are able to apply for work residence permits after arriving in Italy, which might make your bureaucratic process easier. As employers are generally responsible for the work permit application process being self-employed might be tricky. Expat Arrivals has a general guide to getting a work permit in Italy which might be helpful.
Expat Arrivals also has a useful guide to buying property in Italy which might be helpful for finding information on what you will need to purchase land for your wellbeing retreat. Be sure to contact a lawyer in your home country early on in the process to avoid legal issues down the line.
Where in Italy are you looking to buy property and set up your retreat?