When you get into the Minecraft website, there will be a big green button saying “get Minecraft”. This will direct you to the page in which you can choose what device you want to play on, and we want to pick 'computer'. Then, click on Java Edition. After that, it will direct you to the page where you can purchase the game. Click on 'Buy Minecraft' after that. Then, you need to create an account. Since Microsoft has purchased Minecraft from Mojang a long time ago, you will either need to log in to an existing Microsoft account or create a new one. Since I already have an account for Minecraft, I'm not sure what happens next as it just says 'you already own Minecraft, would you like to download it again?'
Once you have purchased Minecraft and have downloaded the installer, open the file and continue on with the setup. Once you finish setting it up and the launcher opens up correctly, all you need to do is click the big green “play” button. This will load Minecraft.
Now you are done!