Get the manual: ENET-UM001C-EN-P and installation instruction 1756-IN019C-EN-P. It will cover most of your questions.
If not:
2 ways to set the IP address:
- If you have another communication device in the rack - use RSlinx and find ENBT on the backplane. Go to Module configuration and setup IP.
- If no over communcation device - use BOOTP server provided with RSlinx installation.
Do not use RSlogix - this is a wrong way of doing this.