Hi there
2wks old is still very little. If he is hungry at the 2.5hr mark and is taking a decent size feed I would go ahead and feed him. If he is not so interested I would wait until 3hrs.
My own DS was still feeding at 2 or 2.5hrs at that age and I didn't stretch him (slowly gradually gently) to 3hrs until 4 to 5 wks old.
As for cues - when mine was a new born I had no idea what his cues were or how to interpret cries then from around 5 wks to 10 months I didn't hear hungry cries because we followed EASY and everything E times were predictable, I had no idea what a hungry cry sounded like! Only a illness which made him need a short time of feeds in the night at 10 months old had me hear his cry of hunger, I was amazed! So don't beat yourself up about cues.