Starting my journey in applying for the D7 visa

Hi!

I'm Lien.  I'm retired and planning to move to Portugal.  I'm American, resident of Texas.  I'm just starting my journey in applying for the D7 visa.  I got lucky and have an appointment with VFS in Houston at the end of Feb.  Now I need help getting all the documents together.  Do I need to hire someone to help me with this?  I understand that the most difficult part maybe finding the 1 year lease.  I'm not quite sure at the moment where I want to settle.  I am thinking I will try first year in Madeira.  And if I don't like it I can move somewhere else the second year.  I spent a month in Lisbon.  I liked it enough, but I wanted to try somewhere where the water is warm and I can do some water sports.

I checked a few agencies that helps with D7 visa, they seem overly pricey.  I can do some of the work myself.  I just need someone to review my application and documentation, answer some clarifications, and I would probably need help finding a lease. 

If you have any advice, please chine in.

Thank you in advance