Enterprise Activation is only for BES users like corporations or if you subscribe to a hosted BES service.
Just ignore that. You need to use the "Manage Internet Email" or "Email Setup" icon to setup your email. Close the setup Wizard and don't bother using it.
You have to purchase a blackberry data plan from your wireless service provider. If you don't have that you won't be able to get any internet on the device. Most CDMA carriers automatically add on the data plan. It does cost extra.