congrats on the gt, i love mine !
first, make a search here on the forums about sov gt, you will find this question has been asked and answered many times.
i set volume to full, it's ONLY the target and not threshold volume, if you don't set it to full you will miss some aspects of the signal that can be helpful in identifying the object (use headphones of course).
go in disc mode initially, it's easier for the start. i use iron mask on, you can go in off initially untill you start recognizing iron falsing better, it happens more with iron mask on. both disc and notch to minimum, threshold mode, and threshold just audible. sensitivity can initially be in auto, although then you should sweep slower. otherwise you can set it to 13-14 o'clock initially, if you don't get a lot falsing you can go to 12 o'clock. and the practice practice practice, after you get the hang of it a bit, change some settings (preferably one at a time) to see how it influences things, the usuall procedure i'm sure you are familiar with from other detectors.
good luck and have fun !