I'm guessing you are asking this from a US perspective.

The Practical Policy of Revolutionary Defeatism

First: Get yourself organised. Action without organisation is either liberalism, anarchism or adventurism. Join the FRSO or the PSL.

Second: your organisation should organise against the war by agitating against the state itself and for peace, but also by hampering the capabilities for continued war, through strikes, protests, road blockages and whatever else is an acceptable method for your organisation.

Third: Survive yourself but also help others survive. Whatever was the US engages in now, there'll be a severe economic impact due to deindustrialization. Your organisation should act to help those most in need, which serves a double function of cementing which side the communists are on (the proletariat) against the interests of the parties with state control.

As a side note, it honestly confuses me how much I need to remind people on a Marxist-Leninist forum that getting organised is the first step. I don't know if this is a cultural US liberal thing of thinking oneself too unique for a movement or too good for a middling party, but that's what it seems like. I'd understand if the complaint was "I don't have time for militancy" but it's usually just "the parties are bad" like a good party is just going to spontaneously manifest itself.