Lines starting with $ mean: You have to paste that stuff in your terminal and execute it (without the $ sign)
- Display hidden files and folders:
$ defaults write com.apple.finder AppleShowAllFiles TRUE;killall Finder
- Always show Library folder:
$ chflags nohidden ~/Library/
- Install Homebrew:
$ /usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"