I want to support leftism because their ideals are wonderful, but all the leftist groups I find are full of traitors that support Russia and China, despite the fact that those two countries are actually fascist instead of communist. What should I do?
Think about it this way: just because a group claims to be socialist or leftist, doesn't exempt them from being fascist. If they support fascism, they're not leftist, no matter what they call themselves.
And that demonstrates that all the leftist groups are not filled with Russia and China supporters... how? I speak out against "communist" governments because they are actually fascist in practice and go against the democratic distribution of power like Marx envisioned.
And that demonstrates that all the leftist groups are not filled with Russia and China supporters… how?
Because it's clear you've never talked to any leftist member of any leftist group ever?
You've completely made up these big bad "Russia and China" supporting "leftists" in your head. Every leftist space I've ever seen in person is full to the brim of anarchists. You have to go out of your way to find these people you think are rampant in leftist circles. What you read online isn't how it works in the real world. You need to get out more and stop believing all this anti-leftist propaganda you're reading online.
Just find a local Democrat group, irl in your area. They likely won't be as progressive as you want, but you can have a voice in the candidates and initiatives they endorse. They also won't be tankies.
While true, in the US, they're the least bad option - you get them or the Republicans, unfortunately. If the fascists aren't kept out of power, you'll have an active slide toward democracy being dismantled and a series of genocides rather than stagnation and any hope of progress toward a leftist utopia. I really hate to say it, but vote blue, no matter who.
That said, unions and union-adjustment groups are a good start for leftist (i.e. non-tankie) groups - they tend to be practical, and the idea of worker enfranchisement rather than autocracy tends to scare tankies away.