I haven’t really touched Owlbear before, but I booted it up and had a play. It has a reputation for being “very lightweight” and boy, it lives up to that. This is great if you don’t want a lot of complicated options - but I don’t see a way in it to “secretly” track a token’s health.
I made this goblin as the GM and the “player” can see the character notes, I don’t really see a way to turn it off (maybe there’s an extension for it.) - If I were running on this, I’d use pen and paper to track health.
If all you need is a quick visualisation to move tokens around, Owlbear is pretty good for that, it’s quick and lightweight and easy to use.
If you’re looking for something with a little more oomph that’s also free, “Roll20” is a very popular free app for running DnD games, it has quite a lot of good tools, can handle full character sheets, and it’s compatable with Beyond20 (Beyond20 is an extension for DnD Beyond that lets you roll dice out of the DnD beyond website into an open vtt.)
If you’re looking for something with a lot of power and flexibility behind it “Foundryvtt” is a system that does everything Roll20 does, usually better, but sometimes a little clunkier (for me, it’s often a bit laggy, and the drawing tools suck - even the “good” modules) - Foundry is really for power users, as you can run independent servers, code your own modules, or install all sorts of mods from the library of modules other people have coded.
If you’re looking to spend a huge number of hours building incredibly pretty 3d environments for your players to explore, “talespire” is available, and seems to be pretty comprehensive… but… oh boy it’s a lot