DHCP for the IP is one way, the other would be to connect to the SPs over IPMI (check docs) and then setup IP with svc_initial_config.

For the license, UEMCLI would be the obvious choice as you have different options for different Operating Systems (doesn't need to be windows).

You can also upload the license file to the system with some scp capable utility, and then setup from within the Unity (uemcli also available there).

You can try RestAPI as well but this may prove too complex.