There’s three feeds: ‘Subscribed’, ‘Local’ and ‘All’.
Subscribed is subs you’ve specifically subscribed to.
Local is subs hosted on the instance you’re using.
All is every damn thing.
You can manually block subs from All, one at a time.
You can manually add subs to Subcribed, one at a time.
Or you can try to find an instance that mostly hosts the kind of thing you want to see, and rely on its ‘local’ feed as your filter.
Because that’s what makes the fediverse different: anyone can make a lemmy server, and they can run it however they want. You want a lemmy for flat earthers, antivaxers, preppers, or young-earth creationists, you can go build one and hook it up to all the others. You can set whatever moderation and content policies you want on the thing, and that’s absolutely fine.
However, other lemmy servers aren’t obliged to communicate with your one. If they don’t like your server, they can ‘defederate’ from it, and refuse to import your content.
It’s a group chat for group-chats; you get separate cliques forming.
For instance, beehaw defederated from a huge chunk of lemmy servers when the reddit shitfire started; they wanted to keep their own vibe, and not have their communities overrun with a giant flood of bots and trolls and maga types. They’re lefty as fuck over there, and they want to keep it that way.
And just recently, lemmy.world (and a bunch of others) defederated from exploding-heads, which was pretty much nothing but trolls and magas and racist fucks.
So it’s possible that you can find a single server with a ‘moderate centrism’ spin and policy to suit, where you’ll only see centrist-friendly subs hosted locally - and that may defederate other servers that are just too lefty for its users. Browse the other communities out there, read their policies, scroll through their local subs. If you find somewhere that works for you, bingo.
But honestly, you may not have a lot of luck. Lemmy started out with a bunch of green-lefty-progressive types, and that still defines a lot of its culture. Lemmy.ml is home to many of the largest communities out there, and though it may not be lefty as fuck, it’s still lefty as heck. The lack of a top-down power structure tends to piss off the right wing, if nothing else. You may find a home for your views, but you’re likely to discover that it has like 3 people on it, so… wooo yeah, party.
If even lemmy.world is too lefty for you, I suspect this may not be your ideal platform.