Can I drive in the state of south Carolina with a UK drivers license only? or do i need an additional international driving license as well?
As long as your license is in full force and effect and applicable to the types of vehicles that you intend to drive in these states, you are fine. You should not require an international driver's license since your license is in English, but you may want to check with the company from which you intend to rent your vehicle. (South Carolina's rules are here; they "strongly recommend" an International Driver's License, but state that this is due to language reasons, which you should not have with a UK license. Georgia's rules are similar less the recommendation for an IDL.
This, of course, assumes that you're just visiting the US as a tourist, and are not taking residence, in which things get more complicated. (You'll be able to drive for a period of time, but there will be a time limit.)
I've hired cars in several US states although not South Carolina and have never needed anything but my UK driving licence.
Assuming you are renting a car, as well as your driving licence you may need a print out of your driving licence information which you can obtain from here https://www.gov.uk/view-driving-licence although most of the big international rental companies do not require this. I've rented from Avis and Hertz in the last year and neither required it, but it's free and useful to have.
Looking on both the RAC IDP site https://www.rac.co.uk/drive/travel/driving-abroad/international-driving-permit/ it states for the USA.
"An International Driving Permit is not a legal requirement but is recommended as, in the event of an accident, some insurance companies will insist on seeing one."