You don't have a WiFi adapter for your PC?
To use USB tethering, you have to set it up in the Settings somewhere so the connection to PC is not charging, but should be data transferring. You probably also need to install LG Mobile driver or PC suite.
Browse articles about LG product repair information, installation guides, troubleshooting, how-to-use and other useful tips for your LG appliances and devices.
www.lg.com
As ch33 has suggested, you shouldn't use smartphone hotspot for multiple devices (or a long term) solution. Constantly use smartphone as a hotspot will shorten its life since your phone probably become very hot.