As somewhat of a beginner myself, if you haven’t already I’d get the fish Washington app, look what’s open, and just start exploring. Books are also a great resource although not necessary if you’re not a reader. Most people here won’t give away there small streams as they’re hard to come by but by doing some research beforehand you should be able to find something worth your time. I’ve found it pretty rewarding and honestly it’s part of the fun to find stuff yourself.
I spend a lot of time in the Leavenworth area visiting my in laws and virtually everything there to Wenatchee is closed to protect ESA listed bull trout, steelhead, and Chinook unless your high elevation or above falls. Sucks because there’s so much good looking water in the area and they live on a fishy looking part of the river. Not sure about east Wenatchee but I imagine it’s mostly gonna be a lake game over there as far as fly fishing goes.
I’d head over Blewett pass if you want small streams and start looking. Once you get past Peshastin Creek, most streams are no longer closed. If you want to fish sometime let me know I’m always exploring new water.