Wow, your question about where to go opens up a can of worms...er...um...flies.
Little Lava is nice, but quite a distance. There are tons of places that you COULD visit; and so little time.
Best advice: go into the water BACKWARDS and SLOW. When you get about waist deep, push a bit w/ your feet and simply sit down. BAM! You are then fishing from a easy chair. LOL And find a gradual incline to go in and back out. When coming out, also walk backwards.
Other good advice: be sure that your fins are on TIGHT. If you lose one, you'll be kicking in circles.
Oregon does not require a life jacket. But a lot of wise peeps wear small ones, the inflatable type I suspect.
Try Olive green and / or Black Woolly Buggers. But, I'd also try Terrestrial patterns this time of year. The fish are trying to fatten up, and love big fat grasshopper, ants, etc.