Welcome to the family!!! Firstly,you would not be allowed to get on gta v online. To make another copy of gta v, just rename your gta v file to sth like "Grand Theft Auto V. After that try to start gta. This will download gta again. I am not sure if this works on the Rockstar Servers but it works on Steam. If you want to play to your "Grand Theft Auto V modded" folder just rename it to "Grand Theft Auto V"