got it, but:
What did you find? 
ipconfig /renew is a Windows command and does literally nothing on any Linux system.
Issuing that command could not have made your internet connection dysfunctional.
All it does is get you a response of:
command not found
as is the case with any invalid input …
What @SimonJ said would probably do what you want on (any) Linux and after a few seconds you’ll get a new lease from the DHCP server on your router - perhaps a different (local) IP address. However, nothing will change towards the outside, where and how the router is connected to the internet and why I asked was to elicit information on why you wanted to do this.
I.E. In a home environment, you are almost always connected to a router via WLAN or LAN which then itself is connected to the Internet and only seldomly are you connected directly to the internet without a router in between.
Renewing your IP address (which you got from that router) would have no effect whatsoever
on the IP address that your router has toward the Internet, which is what you, apparently wanted to change/renew.