First time dispersed camping

Hello r/camping first posting. I am planning on camping in the Gifford Pinchot National Forest here in the middle of September. I had a few questions to ask.

1. We found an awesome spot near a stream, how far away should we be from it? It's not terribly big, but with the rains that Washington gets I'd rather be safe than sorry.

2. Is it safer to place food in a bear bag or a car? (Probably a bear bag due to bears getting into car...)

3. Is there a substitute for fly fishing? I can't afford a rod right now, but would a net and a small calm area work?

4. Recommended defense against wildlife/ bugs? I have a machete, but I'd rather be big/ loud unless needed. Don't have a gun.

5. Anything else I'm missing or fun things to bring?