Can I customize a SharePoint online page using Visual Studio Code and how?

eldocg I would be EXTREMELY cautious when customizing pages using ANY tool. We no longer control upgrades the way we did back in the day. There's no telling what new features could get added to SPO that could break your customization. There's no way to know when they are coming and, most importantly, no way to prevent the updates from happening. 

Best practice to future-proof your SharePoint is to stick with out-of-the-box as much as possible. Or at least be SUPER clear with your stakeholders about the risks and responsibilities for maintenance.