WordPress is kinda weird when it comes to subscribing. There are two kinds of subscriptions (through a WordPress account or through email) and two ways to sign-up for a subscription. To sign up with a WordPress account, you’ll need to set one of those up—or you can just use your email (that’s what I’d recommend).
Subscribing Through the Form
The easiest way to subscribe is through the form. Just scroll to the bottom of any page (including this one), enter an email address, and hit enter. You should be good to go.
Subscribing Through the Widget
The other way to subscribe that looks prettier but can be tricker is through the widget. In the bottom-right corner of the screen, there should be a little opaque button to “Follow.” If it’s not there, you may need to scroll down a bit and then scroll back up to get the widget to appear. Click “Follow” and then follow its instructions.