If you're developing in PHP and need a web server MAMP is probably your best bet.
With that said, my personal approach is to install Homebrew and then install whichever packages I need from there. Of course, either way works.
Regarding text editors, it's a fiercely debated topic here I'd imagine but I'd recommend that you take a look at Atom - it's free and open source and has pretty good Git integration.
I agree completely with JoelTheSuperior. On the Mac MAMP or MAMP Pro (http://www.mamp.info/en/mamp-pro/) are by far the best way to instantly set us a full-stack web development environment.
There are tons of great editors out there. If you are just getting started then Atom (https://atom.io/) would be a great free choice. If you are willing to pay for a polished editor that also has SFTP features then look into applications like Panic's Coda (https://panic.com/), or an old standby BBEdit (http://www.barebones.com/products/bbedit/).