Anarchism

Start growing potatoes and a few varieties of beans, learn how to ferment vodka, and how to safely run a distillation to get alcohol strong enough to sterilise bandages or run a generator (<95% or so)

Get to know your neighbours and look out for one another. Being the person with big ratchet straps, wood planks and tarps, who's also willing to help batten down the hatches is a good way of being part of the community, learn how to make flood defences and how to not die in one.

Get on a first aid course that goes on for more than just a day. Keep your first aid kit and your skills up to date.

Learn to maintain things without killing yourself by touching something charged (physically or electrically) or damaging the thing you're trying to fix.

Get solar panels, charge caravan batteries to run inverters for when the rolling blackouts come.

Find out how to make the chalk paint they put over shop windows for the coming months when the sunlight is unbearable, IR blocking window films also help to keep the indoors from heating up as harshly, while lowering heat loss in the winter, the paint is cheaper but can be washed off when it rains, window films are easier if you're not on the ground floor.

Switch to a renewable energy provider and cancel your amazon/whatever food delivery things you may use (I genuinely dont get why someone would pay double to order a private taxi for a fast food slop meal in the first place let alone the environmental impact of someone taxi-ing food around a city.)

Pester the shit out of your local politicians to focus more on environmental protection, and dont fall for the "voting is pointless, every party is bad" bullshit, because the worst and dumbest people you know are voting for the worst and the dumbest candidates that are ripping the copper out of the walls as we speak.

If things don't get to 3°C and ~2bn deaths by 2050 it'll be through the efforts of the people in power actually being forced to give a shit.