If you want to play a stealthy ranger then you should consider the "Gloomstalker", which was not in EA but will be available at launch. It's a very popular, if not the the most popular, Ranger subclass in D&D and fits the description of what you're going for perfectly.
Now, that doesn't mean you can't play a Beast Master who is stealthy. If you had your heart set on Beast Master, then that's fine, pick that and you'll do fine. But in terms of optimization, you will be better at it by choosing the Gloomstalker for stealth purposes. You can also still get spells like FInd Familur and Speak with Animals if you don't want to lose the animal component of the Ranger.
Will I be able to get a companion that Beast Master gets at level 3? I've looked into the other subclasses, but for some reason, I'm drawn to having a proper pet companion haha! 😂
