If you've recently switched over to macOS from Windows or you just miss the old Start menu, How-To Geek shows you how to add a similar feature to the Mac Dock.
The approach here depends on what exactly it is about the Start menu you like. If you just want quick access to applications, you pretty much just need to drag the Applications folder to your Dock. If you want something closer to a Start menu, with different sections for different types of apps, access to specific files, or whatever else, then you'll need to create a series of aliases inside a single folder. This way, you can stuff all your games into one alias folder, current files into another, and more. It's a pretty clever little method to bring something of a Start menu to a Mac. Head over to How-To Geek for a closer look at how to do it.
How to Add Your Own Custom "Start menu to the macOS Dock [How-To Geek]