See also Radio Frequencies. In SE Portland, Weather Channel 7 (162.550) seems best.
Learning resources
The Multnomah County Amateur Radio Emergency Service is a club dedicated to ham radio, which offers monthly trainings etc. multnomahares.org 
They have downloadable files with many channels, but it's unclear which have practical utility for me. The neighborhood NET channels are worth understanding, and keeping handy.
Recommended: Ham Radio School .
There is a $10 exam associated with that, administered by GLAARG.
This Android app is a recommended study tool: Ham Test Prep
See also
Note, Ham Radio includes FRS frequencies, but is distinct from CB, or Citizens Band Radio . Presumably CB is not an option on Ham Radio devices (?)