The truss rod is a finicky adjustment. For the inexperienced, you should never loosen it more than 1/4 turn every 24 hours, giving the wood time to relax into its looser state.
Before you adjust the truss rod, make sure your bridge height is good. You can do this by fretting notes above the 15th fret or so, and bending, shaking, etc, at points all across the strings and frets above that point. Raise or lower as needed or desired.
Then move on to the truss rod. If you’re fretting out (buzz) on any frets below 12th, you either have high fret(s) or need a truss rod adjustment. If there’s buzzing, you need to LOOSEN the truss rod, to allow more bow or RELIEF between the frets and the strings. Loosen no more than 1/4 turn, tune, and then let the guitar sit for ~24 hours. Retune, and check for buzz again. If still buzzing, loosen another 1/4 turn and wait another 24 hours.
If you do this several times, and it looks like the strings are getting WAY too far above the fretboard and you still have buzz, you likely have a high fret or a warp somewhere, and you should take it to a luthier for a good setup. Let him or her know why you’re there, and also that you tried to make adjustments yourself.