ACMarket is a free alternative to the official Android app store, but it's worth noting that it's not completely safe. Many applications on the official play store require rooting. The best way to download ACMarket is to use an Android emulator. The two most popular emulators are BlueStacks and Nox Player. Once you have an emulator, you can install the app by placing it into the Android emulator.
https://apkgenk.com/acmarket/