Sorry to hear that you are still facing this issue.
Let’s clarify a few items:
– MAMP is running and both the Apache Server and MySQL Server are showing that they are running (boxes are black)
– From the MAMP control panel > Preferences > Ports > click Set Web & MySQL ports to 80 & 3306
– The MAMP start page opens when you click the link on the MAMP control panel
With MAMP set up this way, then the details you provided earlier should work; I just tried it on my own local MAMP install.
DB Name: gardewine
DB User: root
DB Pwd: root
DB Host: localhost
Note that with the Apache port set to 80, you may get a warning that the port is already in use. This is generally caused by one or both of Skype running and Microsoft World Wide Web Publishing service is running. I’d have to look up the links to where you can find out how to disable them, but Google should work ??
Also note that with the port set to 80 you will access the site install with:
https://localhost/gardewine
… that’s if gardewine is the name of the folder in htdocs where your WP install is.