You may show them the place, but do not accept the booking outside of Airbnb platform. This may be cheaper for them, but these dates will not count in favor of your performance. Furthermore, you will not have any protection against misconduct or damage.
Therefore, let them see, and then, direct them to make a booking through Airbnb platform. Only in this way, your performance will increase and all communication and payments will go through the platform, so there will be records of these activities.
Write house rules (for example, no smoking, no parties, no pets, quiet hours, ...). By booking the accommodation, guests agree to these rules.
Take a damage deposit, which will be returned on checkout, upon inspection.
Besides Airbnb, make sure to follow local laws in your country in accordance with short term rentals - for example, take guests' passports and register them in official registry (or whichever rules are applicable in your country).
By taking all these precautions, guests will certainly pay attention on their behaviour and take care of your property!