Your WordPress subscription is ready with Jetpack installed upon your WordPress hosting is created on our WordPress server.
However, there's a little bit of manual activation to be done due to Jetpack require your WordPress domain to be accessible for validation via the public Internet before your domain can be provisioned with any Jetpack plan.
After activating and installing Jetpack, you’ll need to connect it to WordPress.com. A WordPress.com account is required so that Jetpack can provide your site with stats and analytics about your traffic, site security, faster content delivery, sharing tools and multiple site management from one interface.
You only need one account to access all Jetpack services (including VaultPress, Akismet, Polldaddy, Gravatar, and WordPress.com itself) so if you already use any of these services you already have a WordPress.com account which you can use for Jetpack.
Please refer here for the complete instructions on the installation steps.