Do upvotes and downvotes work the same as reddit? I mean, I'm usually a lurker and mainly upvote posts and comments that are good. Does it affect "hot" and "active" sorting of posts and comments?
Yes, but the algorithm for sorting is slightly different on Lemmy. It's also slightly buggy. Hot on Lemmy has the time weigh significantly heavier than on Reddit's Hot. In other words, it's much easier to drop off the Hot page the longer your post has been up. It helps promote cycling of new content and gives new posts a chance to get seen.
Active sorts by the number of comments, not by votes iirc