I installed the openwrt firmware and it does not give me internet, it connects to the other router but does not transmit the wifi signal or anyone else. Connection goes up to the router, but do go out of it.
Wireless is typically not enabled at boot. It needs to be "turned on" through either the command-line or LuCI (GUI) interface.
Have you configured your WAN interface with the proper protocol for your ISP or transport provider?