I''m buying a home in a adult community. Can you please tell me what are the advantage and disadvantage of buying a home and you don''t owe the land?

If there are restrictions, rules, common ownership, you could deal with decisions with which you are not necessarily pleased.  Dues increases, etc.  However, assuming you are comfortable with all of the contractual documents disclosed up front, some of these communities can be great because of the various amenities.