I then have an index.php file inside the new host and when I enter newdev:8888/index.php it says I'm ready to go (or something like that!) I set up a new database and called is newdev (for consistency) with a New User and PW
The next instructions were where I think I've messed up. The host folder is on the same level as the localhost folder, as was also recommended.
The host folder resides in my Sites folder on my HD. I have been able to create a new host - for the sake of this discussion I will call it newdev. This is where I have faultered, as most of the videos I have reviewed outline how to set up a new site in MAMP and leave out the link between starting MAMP and working on an existing site.
However, this is the first time I need to take my existing live site, make a backup (Akeeba), then work on it in MAMP on my home computer. In the past I have been successful, after trial and error (lots), of starting a new joomla site in MAMP, then sending it up to a host. I am getting nowhere trying to find some tips or videos on how to work locally on a backup I made of my existing site.