First thing is to login to your azure subscription and you will land on the page shown below Select the web app and a wizard will startup, fill out all the fields, subscription, resource group, name, operating system and what region you want the web app to be deployed to. Shown below. Click on review

Login to your Microsoft Azure account, proceed to the Azure marketplace. It looks something like this: Up on the top where you see the red arrow type wordpress and this is what you will get below. There are lots of wordpresses to chose from, for this deployment I going to pick the first on the