Iridium activations can typically be done same day, Monday thru Friday, during normal business hours. Activation details, including your Iridium phone number and expiry date, will by forwarded by email, typically within 24 hours of activation.
The iridium network has extremely limited internet capabilites, for now. Only GO! approved apps can currently access the connection through the go - What's app and Messenger are not included in the list as of yet.
There are other devices that give a more open internet connection these apps will work over such as the Inmarsat ISavi. This pointed device opens a true internet connection and is geared for internet, unlike the GO!