re: Advice on when to book my flight

It used to be about 5 months out for international and about 45 days out of domestic (not always, but that would be the estimate when I felt like I was getting the best deal), but with COVID and constantly changing fares, I would just book when you like the price. Most of the airlines are offering free cancellation with credit, so if you see the price go down, just cancel and use the credit to rebook at a lower price.