Step 1. Install Xcode. Xcode is Apple's Integrated Development Environment (IDE). You can get Xcode in the Apple appstore.
Step 2. Launch Terminal. Go to Launchpad – Other – Terminal
Step 3. Install HomeBrew. Homebrew installs the stuff you need. Homebrew is a package manager for Mac OS
/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
Step 4. Install Python3. Python 2.7 comes pre-installed with Mac.
brew install python3
Step 5. Download Sublime - https://www.sublimetext.com