@Lisa6611, @Sergei--and--Larina0
I noted the GST/HST to minimize assumptions that all rentals would qualify.
GST/HST is CRA federal and it flows down to rhe Provincial level. So, to give guests the Staycation Tax Credit, you would need to register. There is no link to Municipal jurisdictions.
That being said, in Ontario, you only need to register if you make more than $30,000. However, you can register voluntarily if your sales are less. There can be GST/HST benefits of collecting and remitting, even if your sales are less than $30,000.
Ultimately, it would be in your best interest to consult a tax accountant who can give you the legal advice.
Do not hold me to providing advice, my comments are for suggestion only.