I'm fairly new to the fediverse, but my understanding is that different platforms are supposed to be able to share content between them. I have always hated most social media and reddit was the only one whose layout I could stand, so my favorite fediverse platform is Lemmy. I do have a mastodon account but if I can get the same content here I'd rather just delete it and use a platform I like. Is that how it works? If so how do I do that/know when I'm doing it?
You could try creating an account on kbin/mbin instead of lemmy, my understanding is that that gives you the "threadiverse" and the microblogging fediverse on one platform, though I have not tried it yet.
On Lemmy you can only follow communities, not individuals.