Firstly, login to your MSDN subscription Account and go to MSDN Subscriptions. You will see different Subscription benefits as shown below. Scroll down the page you will see the "Microsoft Azure" section there. Click on "Activate Microsoft Azure".
You will be redirected to the “Microsoft Azure” Sign up page as shown below. You must have to enter your “phone number”, tick the checkboxes that are highlighted below. Then, click on “Sign Up” button at the end of page.
You will be redirected to another page as shown below. Wait until the page loads. Then, you have to click on “Start managing my service” there.
You will be redirected to another page, which takes couple of minutes (depending upon your internet speed) to load the Azure. The display will look like as shown below:
Finally, you will get the preview as shown below, which indicate that your AZURE is activated.
Happy using AZURE! Happy coding!