I use both Hexbear.net and Lemmy.ml.

Hexbear.net is Left-Unity and anti-sectarian, there are lots of MLs and Anarchists there alike.

Lemmy.ml is admin’d by MLs, but has Anarchists in the moderators as well. Technically Lemmy.ml does not take a firm stance politically overall, but by virtue of the makeup of the moderators and admins it leans heavily socialist.

Speaking of Marxism-Leninism, I made an introductory guide to Marxism-Leninism in case anyone is interested. With the aftermath of the US election, now is a great time to begin reading theory, as it helps us analyze our current struggles and how we can move beyond them. Open for feedback!