You’ll see the same communities/magazine no matter what’s the instance you use.

Important caveat that, while all instances have equal access to all communities (barring defedaration), communities won’t show up for instance users until at least one user has subscribed to it. Some instances use bots to automatically federate new communities, but it’s not a guarantee. That said, World will likely have the most comprehensive access to other communities given the size of its active user base.