Join your local DSA and tend to local issues. The things that the national level are indeed serious, but spend your time and efforts where you can make the biggest difference.
Donate a few dollars to your local land trust to keep land out of the hands of big business.
Join local housing boards or City Hall meetings, wherever decisions on zoning and housing are decided. Anytime someone tries to blame something on bigger buildings designed for more people, and better public transportation, fight them tooth and nail. Single residence zoning, parking minimums, etc. are one of the reasons homelessness exists.
Show up to protests
Make friends with your neighbors
Please do anything but just vegetate. You are important. But only if you help.
That's basically cuban internet