1) connecting to an analogue phone line is not possible!
these are IP Phones and so intended to work with a TCP/IP network
2) apart from that you need a 48Volt power adapter if you do not use PoE (power over ethernet -> using a network connection)
3) this device probably has a cisco SCCP image for use with a call manager
-> if so, you cannot use this phone with this firmware as "stand alone"
you may be able to convert tho phone to using SIP
Solved: Configure 7965 with SIP - Cisco Community