Running a volunteer project in an anarchist way doesn't just mean that you declare everyone "equal" and let people sort things out by themselves with no guidance. That gets you debate club, not anarchism.

Far more important is that you balance responsibility and authority - do not give people authority without the corresponding responsibility, and do not give people responsibility without the corresponding authority.

Why? Because people usually need some degree of 'ownership' over the tasks that they take on, otherwise you will get nothing but endless arguments and it's not clear how the outcome is going to be decided, or by whom.

Once you have that balanced correctly, it becomes a matter of keeping tasks (and areas of responsibility) small, and ensuring that nobody has an outsized amount of them - people should not take on more than they can reasonably handle, even if that means that some things don't get done.

Beyond that, you need the usual things in any collective project - a safe, constructive and supportive environment, people to go to for help if you get stuck, and a whole lot of conflict resolution work and training.