Lemmy’s default sort is “Active” - which I believe is “most recent comment activity”
The classic reddit experience is most like the “Hot” sort option.
Lemmy’s other weird default is the “feed” which can be all, local, and following. Lemmy defaults to “local”, which is probably not what you want (chronological feed of posts on your home server)
Also highly recommend “blocking” communities if you don’t want to see their content. (Mostly important if you browse the “All” or “local” feeds)