I've looked all over the internet for this, and since I'm new to Emacs, I don't know what to search for. I'm not looking for mini-buffer completion for commands and such. I'm looking for code hints in the mini-buffer, as shown in this gif. I couldn't care less about the fancy parens, the code hints are awesome. How do I get them?
You need M-x
eldoc-mode. It's enabled by default in 24.5.