MAMP local install on Mac

Trying to install wordpress on my mac locally, have spent the day (off an on, not 8 hours!) reading and re-reading the steps. Everything seems to makes sense until I get to the line that starts: “Then in the browser, go to localhost:post/folder_renamed…” I know its something painfully simple and obvious, but I just can’t figure out how to actually complete that step…

Any help would be appreciated.