I really encourage people to organize hyper-locally. It's hard to change the world if you don't know the names of the people on your street or in your neighborhood or who your local elected officials are.
We are unfortunately limited on what federally-elected Democrats can do until midterms. That’s math.
But get involved in your school boards, township councils, and municipal elections. When they turn blue or solidly blue, we move up.
Local elections calendar:
https://ballotpedia.org/Local_elections_calendar