If you are starting from a blank configuration, all interfaces are shutdown. Check this with command "show ip interface brief" and correct it with the "no shutdown" command in the interface configuration.
Here is a basic starting configuration for you to paste into your router to get things started. Please change sections in upper case lettering between asterisks. Not all of the interface configuration lines are needed, especially if your IOS does not support a few of them. Just make sure that the IP address is set and that the interface is not shutdown.
*****no service pad no service config no service finger no service tcp-small-servers no service udp-small-servers service timestamps debug datetime msec localtime show-timezone service timestamps log datetime msec localtime show-timezone service password-encryption ! hostname *YOUR_ROUTER_NAME* ! no aaa new-model ! enable secret *YOUR_ENABLE_PASSWORD* no enable password ! clock timezone *YOUR_TIMEZONE_NAME* *YOUR_TIMEZONE_+_OR_-_VALUE* clock summer-time EST recurring 2 Sun Mar 2:00 2 Sun Nov 2:00 ! ip subnet-zero no ip source-route no ip domain-lookup ip domain-name *YOUR_DOMAIN_NAME* ! no ip http server no ip http secure-server ! interface FastEthernet0/0 description *YOUR_INTERFACE_DESCRIPTION* ip address *YOUR_IP_ADDRESS_INFORMATION* no ip redirects no ip unreachables no ip proxy-arp no ip mroute-cache ip verify unicast reverse-path no shutdown ! interface Serial0/1 description *YOUR_INTERFACE_DESCRIPTION* ip address *YOUR_IP_ADDRESS_INFORMATION* no ip redirects no ip unreachables no ip proxy-arp no ip mroute-cache ip verify unicast reverse-path no shutdown ! logging buffered 16384 debugging logging console informational logging monitor debugging logging trap debugging ! banner login ^
*YOUR_LOGIN_BANNER_MESSAGE_HERE* ^ ! line aux 0 no exec transport input none line con 0 exec-timeout 15 0 password *YOUR_LOGIN_PASSWORD* line vty 0 15 exec-timeout 15 0 password *YOUR_LOGIN_PASSWORD* transport input telnet transport output telnet ! end