LaTeX is a typesetting tool, the de facto standard for scientific publications.
I used to only install BasicTeX and install additional packages using
sudo tlmgr install <module_name>. I no longer use, or recommend, that solution.
Instead I install the whole MacTeX system. It takes ~4GB of disk space, but it saves time in the long run.
For editing TeX, I now use Texpad, which is the best editor by far. Even better than emacs or my esteemed Textmate. I just wish it had more user-friendly templates and customizable shortcuts. In other machines (or when working with non-tech people), I use the wonderful web-based Overleaf.
For managing my references, I am now using miscellaneous bib files in my different project and paper folders. I gave up on Papers.app and Mendeley a while ago. To find Bibtex, I prefer DBLP to Google Scholar, as it consistently provides me with better details.