Usually, it's only a matter of time until your download starts. If your download status seems to be stuck on the 'Initializing' phase, stay calm and wait.It can always be worth a try restarting your modem and/or router. Make sure that your internet connection is stable and that you're not experiencing any other issues with your network.
Check your internet connection: Slow download speeds may be due to issues with your internet connection.Let's get to the things you should take a look at when you're experiencing slow download speed on : : How To Fix Slow Download Speed Make sure you didn't manually limit the download bandwidth in the settings. To check this, run a speedtest – the easiest way to do so is to type 'speed test' into the Google search bar and click on the Internet speed test widget in the results. If you tried all the following options and your download speed still doesn't reach your bandwidth capacity, the reason could also be that Blizzard is manually throttling the download speed to a certain limit.