I'm new here, how do I get the apps on the BuildStore?

First of all, welcome! Glad to have you :)
To install the apps that are available, you must register for an account using this link. After you finish the registration process, tap “Register this device” button on the device you want to associate with your account. Then, you will be asked to accept the installation of the provisioning profile, accept it. After that, you must make a payment for your device and proceed to the home page, or go to "Apps" from your account page. Tap the "Install" button near the application you would like to install and you will be asked if you would like to install the application on your registered device.
Voila, like magic!