No, it makes very very little difference, I graduated late by about two years and took a gap year after that, too (most people getting PhDs take a gap). People getting into the workforce immediately usually don’t have a huge advantage, either, although they go get a little more pay since they work slightly longer in their lifetime.
What’s generally more important is how you position yourself after graduation. Internships if business, lab if grad school, etc. It’s very easy to shoot ahead or fall very behind, though, as life after graduation is pretty much a matter of luck.
There’s probably some, but keep in mind that your instance has to be federated with them and lemmy.world generally defederates a lot of the more extreme instances (plus a few benign but potentially illegal instances, since the admins don’t want legal trouble.)
That said, Lemmy historically is rather extreme “left” (if you can call it that lol) so much so that the .ml of lemmy.ml stands for Marxist-Leninst. That starting point kinda makes the rest of us the conservatives of the community.
If you want to feel challenged, look into who we defederate from. Hexbear, lemmygrad, beehaw, etc. I’m sure those rabbit holes will be new to you, although heaven help you lol