Yes it is coding time!
We are going to use a simple template to explain the 4 parts of a trading robot (also called EA or Expert Advisor in the context of MT4). Download this file from https://github.com/Lucas170/Chapter-1-All-Files. Download it as a ZIP format (there's a button on the bottom right). This ZIP file should contain a file named C1_BasicEATemplate.mq4.
In your MT4 platform, under file, click “Open Data Folder”. Go into the MQL4 folder, there should be an Experts folder. Place C1_BasicEATemplate.mq4 in the Experts folder.
For Mac/PlayOnMac Users: Find the MQL4/experts folder in Finder under <user>/Library/PlayOnMac/wineprefix/...