The first step

Before you can do anything with Watson, you need to set up an account (and for general discovery, you can use the free version!) and log in. You can get started with IBM Watson by going directly to: https://watson.analytics.ibmcloud.com (as of this writing) and (or course!) using user your IBM ID to sign-in (or sign-up if you're a new user).

Not too much more to add here on this topic, as logging in is pretty much self-explanatory.