I am happy to share that after a long time trying to install Lightning locally, I finally got it running!
You can see it live here: http://localhost:4000/projects/d439ff88-b824-4868-a94c-d0e7419175c6/w/7420633f-3880-4e96-9800-270cf231a395?job=b4e20c14-74e0-471b-87fe-a2b4fe4ae707
After setting up Node, Elixir, Phoenix, and Lightning, fetching and connecting the adaptors, and connecting the worker, I now have a fully running local Lightning environment.
It feels great to finally see everything working after overcoming all the errors and setup challenges. Now I can start testing adaptors and developing workflows locally