Then show up and fuckin yell at them. It's free and the cops can't stop you. We had people showing up yelling at our council about some mean shit some other person said to them because they publicly supported Israel, like it was kindergarten hour (I mean, fuck around and find out, though, right?), and they had to just sit there and listen until her time was up. Somebody else came up and personally put one of the councilors on blast by name, the dude looked like he was going to have an aneurysm but they had to deal with it because they're part of the government and that's freedom of speech.

Look, you don't have to join city council, there's other movements out there that are looking for people like you. Try formally joining some or joining some of their actions:

https://rebellion.global/ for extinction rebellion (climate change action)

https://blacklivesmatter.com/ this one's pretty obvious, I think.

There's also YIMBY (Yes In My Back Yard) groups all over the country, you could try looking for one where you live and/or getting one together by putting up flyers at coffee shops, nearby colleges, anywhere that'll let you put one up and maybe a few places that won't.

Look, I'm not even going to tell you to think about federal politics because it's moot. The parties want you to believe that it's the most important place to put your time/money/attention, but that's bullshit. Spoiler alert: one of two fossils are likely to win, one of them is a self-serving Nazi, the other is Joe Biden, do with that information what you will. Local politics is where shit gets done in this country, and it's a lot more impressive to local politics when you can show up either consistently or with a group of people.