In Maine, mobile homes on leased land (in a park) are considered personal property. Most towns will assess real estate tax on the value of the home. But the assessment is only on the value of the structure. The land owner pays real estate taxes on the land.
You need to speak to your Realtor or your attorney. This should have been spelled out in the contract and closing documents. I'm assuming you do not own the land and you probably pay lot rent to whomever owns the land? I would presume the owner of the land pays the property taxes. But then again...I'm not there and not familiar with your contract or the property in question. Good luck!