So I currently live in Washington and I’m supposed to be flying to San Diego the 21st of this month. Will I only need my ID in order to fly from Portland?

U will need ID any time that u fly from any airport

You will need government-issued photo ID. They don't care where you live, just that you can prove you are the person to whom the airline issued the boarding pass!

Yes. They require id to fly.

You will need a valid government-issued photo ID for all domestic flights.