YITH WooCommerce Subscription is a plugin designed to enable recurring payments for the services offered in your shop.
To start using them together, just make sure you have installed and activated both plugins from the Plugins menu in your WordPress dashboard.
You will see the My subscription menu automatically appear in the list of endpoints in YITH > Customize My Account Page.
You can either keep it as is so it will automatically show users all their subscriptions or customize it with custom content.
For more details about the configuration of YITH Subscription, please, refer to the official plugin documentation.