What do hikers need to watch out for in the Pacific Northwest?

I’ve been living in the Seattle for almost 2 years. I love to hike and have frequently gone on solo day hikes before. When I lived in Tucson, for more than 20 years, I knew what the dangers were and where to go and how to prepare for hikes. Here I’ve walked around the city and near the city a lot, but I’ve only been on a handful of out-of-town day hikes because I’m not as sure about how to prepare. So, what do I need to know about bears and raccoons and other things in the woods that I never had to worry about before? I know the desert pretty well and I need to know the forests.