How to upload my app to Google Play Store?

For specifics, I'd check Google's guides starting here

ELI5 Version:

Imagine your app as a new Lego set that you're building to distribute to the world. In your development environment, you have access to unlimited quantities of any imaginable Lego brick.

1. You assemble, disassemble, and re-assemble your item until you have what you want the final product to look like. (Develop your app)
2. You compile a list of instructions used to build your final product. (Creating your manifest.json)
3. You collect all the pieces you used to build your final product, and break them into smaller baggies to make building the final product easier for everyone that purchases it. You place these baggies into your final product boxing. (Build your app)
4. You take some sample images of your completed final product to put on your box. (Marketing materials to be uploaded to the Play Store)
5. You send your box off to the Lego store (Upload to the play store)
6. The Lego store officials review your set and make sure it passes their standards (App reviewed by Google)
7. The Lego store puts your box in their magic machine, which helps make your box art look prettier and has the ability to clone your box for anyone that wants to purchase it. (Google Play preps to distribute your app. By being on the play store, your app gains credibility)
8. Your Lego set is available to purchase! (Your app is live in the play store!)