What are you spraying for? If the tree has not experienced any disease or insect issue previously, then there is really no need to spray.

I was spraying to prevent PLC which is supposed to be more common in our area and something you can't really treat within the season if it pops up. It seems a lot of people spray as a preventive or to get a head start on control of common pests, but perhaps I misunderstood. As I said before I am a newbie with peaches. I grow citrus and have figured that out for the most part but peaches and apples I haven't gathered enough info/experience with. To my inexperienced eye my tree had no issue last year,other than my puppy deciding the trunk was a chew toy but it still pulled through. It produced two large bland peaches (after thinning) and I attribute that to the age of the tree. But while reading through this forum I see many people make reference to spraying their trees after fruit set every few weeks until harvest. I've seen some reasons being insect/brown rot control and others common peach maintenance but I don't know for sure. I used to be a take it as it comes gardener but I have spent too much time and money on plants that end up dying over the years to do that again if I can help it. So if anyone has any suggestions on what I can spray preventatively or common Peach pest/disease in the PNW I should be on watch for I would greatly appreciate it!

I have not seen Bonanza subject to leaf curl here, the same with Frost peach (which is noted as being PLC resistant). Those are really the only two varieties of peach I recommend for west of the Cascades. You can certainly do another dormant spray now (with fungicide) before significant bud swell but before green tips.

Here in SE WI I usually spray my peaches to prevent peach leaf curl with a fungicide product containing chlorothalonil. Normally I spray once sometime march 15th-April 5th. In 2016 we had such a warm March that I sprayed in early March. This year in February we had a warm spell with over 5 days at 50-70 degrees so I sprayed last weekend just to be sure I got it done before the bud scales cracked.

I know some use copper but chlorothalonil works great for me. Bonus is I can use it on cherry leaf spot on my cherry trees (after harvest) and also commonly used for tomatoes for preventing early blight. With copper, I would not have much use for it after spraying for PLC. I guess whatever works best but spray while dormant and before bud scales crack to get good control over peach leaf curl.