From most hype to least hype: Owl House, Amphibia, Casagrandes, Infinity Train.
Luz is cute as fug, and her show seems to have the most interesting premise. Magic and monsters, just like Star, except it seems Luz will be in a magical setting right from the get-go, so there won't be any growing pains like Star Vs did in season 3 when it transitioned from the Earth setting to the Mewni setting.
Anne isn't quite as cute as Luz, but I liked what I saw in the theme song, like the marshy setting and the monsters. The theme song seems like the enemies will just be bestial monsters, but an antagonist humanoid frog was seen in promotional material. I think more people pay attention to Luz's show because it has more magic involved. Anne doesn't seem to use any magic, and I have a hunch her show will have more of a wilderness/rural vs industrial/civilization theme.
I was a big fan of Ronnie Anne in The Loud House, but her extended family have already appeared in a few episodes and haven't really won me over. I think I would have been looking more forward to the spinoff if it was just about RA's immediate family. As things are, I'm ambivalent towards it. Plus, it's a very mundane setting compared to the other two.
Infinity Train's looks painfully low-budget compared to the other three, and I didn't really like Tulip much in the pilot.