Should I root my LG 4G phone in order to reverse tether it?

[AC Question]

I just got my first phone, a LG 4G, and I want to use it at home but my wifi does not work with mobile devices, so I'm ending up using a lot more data than I would like to. I want to reverse tether my phone to my desktop's internet connection, but I was told I have to root it in order to do this. I don't really know much about phones so I would like some opinions on whether or not I should do this? Like, is it illegal or will it damage my phone? Is it safe to do?
Any information on this topic would be amazing since I'm very new to phones.