Welcome! I was right where you are a few months ago and it can feel like a lot to get right all at once, can't it?
The high quality air purifier is a great tool, and keeping windows closed is always a must. Depending on your window construction and humidity and whether you're likely to have issues with mold, increasing humidity can help respiratory health in general - my vet has recommended this in the past for my non-bird pets too (cat with lung issues). I've also put wet towels across the bottom of the windows where mine had little gaps - basically anywhere that I feel a draft in winter, I block with wet towels in smoky conditions.
I already had a $$$$ air purifier when I got Cotton, but I ended up buying an air quality monitor that I can move from room to room and find out where the best spot is. My neighbors had a garage fire a few months ago, and I had to have some work done on my house -- it was so helpful to my peace of mind to know the room Cotton was in had no particulates floating around.
Other more random things friends in fire country have told me over the years -
I don't have central air conditioning, but if you do it's important to make sure it's recirculating and not pulling air in from outside.
If you're in a house with a furnace, making sure your furnace filter is changed, and changing both furnace filters and air purifier filters after fire season (or more often during fire season depending on the year).
I love your windows, by the way! So pretty even if the sky isn't at the moment
