I am well, thanks. How are you?
If I understand correctly, you wanted to rent out the house for two years, but start with a one month trial just to make sure everything was okay.
I think this is possible. The minimum stay on Airbnb is one night, but you can set your minimum stay at 28 nights or more, and then the long term cancellation policies apply (you can select which one you want, flexible, firm or strict).
In terms of the maximum stay, I have mine set at 180 days, i.e. six months, but when I go to the settings and put in 720 days, i.e. two years, it does allow me to do this. Was the problem that you were trying to extend the guest's stay from one month to two years? If so, perhaps you could have done the remainder of the stay as a separate booking.
However, I would probably advise against doing this kind of long let on Airbnb. Firstly, both you and the guest are paying Airbnb fees, and these will add up over such a long stay to a huge amount, which I don't think is justifiable to the guest. After all, you might be paying Airbnb to advertise your listing and handle the payments, but the guest is paying just to find you and they will end up paying $$$$ for that privilege!
Of course, it's nice to have the payments handled for you, but beware! Airbnb take the payment for the first month up front and then takes payments monthly after that. If the guest doesn't have the funds on their payment method, or cancels that payment method, and Airbnb cannot collect the funds at any point, there is nothing they can do about it and you could be stuck with a squatter.
Also, do you know about tenants rights in your area? This is something to seriously consider before doing any long term bookings.
Airbnb's verification process is very limited compared to landlord or letting agency checks. For this length of stay, you want to get references, both from previous landlords and the person's employer. Perhaps also a credit check. You want a proper deposit, which is something Airbnb does not provide. You want landlord's insurance, because there is no guarantee of Aircover paying for damages, let alone covering you if the guest stops paying the rent.
I think, in most cases, for this length of stay, it is better to do a normal long term rental contract and take a deposit. Of course, you can use Airbnb to find the tenant and book the first month's 'trial'. Then, if you are happy, you organise the contract with the tenant directly. You will have both paid Airbnb handsomely already for helping you to find each other and handling the first month's payment. I don't think you need to continue paying fees for two years!