Trimming Shimano FD-R3000 front derailleur
Based on my interpretation of the text of the Dealer's Manual for your Sora derailleur, there is only one trim position which is a when after shifting onto the big ring from the small ring, actuation of the small, lever B, will move the derailleur slightly inboard while still aligning the chain to continue on the big wheel. See page 9 of the manual.  Now this trim position is meant to be used when you're in the large ring and beginning to shift up the cassette, at some point, usually around the 2nd or 3rd largest sprocket, the increasing chain angle may cause the chain to rub the inside cage of the derailleur making noise.  The trim feature kicks the derailleur slightly inboard--enough to stop the noise without actuating a shift off the big ring.

What is suspicious in your case as described is that you experienced noise when in the big ring and moving out on your cassette.  This is odd, because if things are in proper alignment, this large ring--smaller sprocket combination should yield a more proper chainline---the chain runs straighter.  Therefore, I suspect you need to check the initial alignment of the front derailleur: the outer cage plate should be 1-3mm (and the closer, the better) above the teeth of the big ring and absolutely parallel to it.  You should be able to take a hex key or any straight edge and while touching the outside edge of the outer cage plate, the other side of the straight edge should contact the outside of the large chainwheel, laying flat against the two. This is your necessary starting point.