How do I pick one?

I picked for you, it's https://hachyderm.io

That looks to have some pretty radical politics at its core. No thanks.

What is it you were looking to partake in? Racism, violence, fascism, colonialism, white supremacy, religious extremism, nationalism, homophobia, or transphobia?

Pick at random, or find one with a theme you enjoy. You can always move off it; a few clicks and your followers migrate over to the new one.