Can you host your own server from your computer/for free?
use the search function next time this has been asked 100000000000000000000000 times before
At the moment no.
Using SteamCMD gives you a funny message from Garry.
The only way at the moment is to use a server host.
Here is a list of hosts. http://playrustwiki.com/wiki/List_of_Server_Providers