Once you access this option, you'll see several icons, some of which correspond to apps installed by default and one in particular called System applications that includes different basic tools. You should be interested in visiting My Applications, the option on the utmost left side of the upper menu. If you take a look at the upper part of the interface, you'll see several sections.
Once it's ready, you'll be on the main screen of the emulator, very similar to the home screen of any phone or tablet. It's one of the most stable and user-friendly options. The fastest way to access the store from Windows is by using an emulator of the likes of BlueStacks. Thus, you can download and use apps from this store and even run them or create your own backup.
If you want to access the Google marketplace from your PC's desktop, there's an easy way to do so. It works with a Google account, which is compulsory on this operating system, and that's where we can find both free and paid apps. The app that grants us with access to the store is installed by default on many devices and it's the easiest way to download and install apps on our handset. Android devices come along with an app store to download contents, the Google Play Store.