SIP Servers can be created and configured in the MManage -> Users and Devices -> SIP Server.
Click on the sipserver_template -> click New User button -> popup window: click Yes.

You can configure the new server in the edit tab:
Fill in the IP field, which is the address where the server will direct calls.
This field can also contain a domain name instead of IP address.

From the options in the Authorization drop-down list, select Username/Password must match.
Finally, fill in the SIP username and password at the bottom of the page (the section labeled Proxy Authentication).

In most cases the rest of the settings are better to be left as they are.

When finished creating and configuring the SIP Server, go to MManage -> Routing -> Routing and add the server to the routing.

Regarding your second question, I attached a price list for all destinations.
We can configure the routing  after you prepay for the service.