if u root your device u will void your warranty so if you are newbie it is advisable to not root your device.there is a risk of bricking your device during the root process
and i think there are alternative solutions of using tethering without rooting just google it and find out
hmm.. I rooted my droid razr but i haven't really delved into the rooting of the s4. I mainly wanted to now if this was a viable option. doing research into the options.