Is there a way on lemmy to have small communities new post always come up on the top of your feed?

Choosing "all/new" gets the job done.

And many Lemmy clients have more options with additional cleverness to get a feed with a mix of fresh and familiar.

It's worth pointing out (to communities thinking about moving) that there's nothing algorithmically suppressing new content here.

Getting (and staying) noticed is way easier, here.