it's not like getting a kitten or a puppy. it's a much deeper commitment, more like having a child.
I dunno about that. Not into cats, but now you've made me think about it, my puppies & my kids are probably a 'deeper commitment' than my horses, because they live happily in a paddock & eat grass, where as my kids & dogs need to live with me, rely on me for everything... Unless you're talking a greater financial commitment... horses def up there with kids then, above dogs & kitties!
Now, welcome OP!
How exciting for you! Good for you - & the horse you end up with - that you're smart enough to do your homework *before* you get the animal! Keep it up... because the more you learn, the more you find you don't know!
And learn from everywhere you can, but careful not to take advice blindly, because for every 10 horsepeople you ask a question of, you're likely to get at least 15 opinions!
I second(or is it third??) the suggestion to go to local stables & such, to get some on-hand experience. Learning theories & principles from books & such is great, but there's a lot you can't learn that way, only from experience.
What size does a stable need to be? How can I get a stable? What is the best feed to use? What is the best forage to use? How can I tame the horse? What is the best breed of horse for beginners?
Sometimes stabling horses is a necessity, and it's handy to have one, but horses are best kept more naturally. Paddocked with other horses. A large stable, with other horses around is best. Not sure about the 'how do I get a stable?'... Buy some timber, nails, tools? Employ a builder?
Horses are 'trickle feeders', built for small but near constant amounts of roughage going through their system. Rich, large & infrequent feeding can be problematic for them. So basic diet of free choice grass hay/grass is generally best. Depends on weight, workload, health, how you're able to feed, etc, etc as to whether/what else you may need to feed a horse.
By all means, learning about horse psychogy & training is important, but 'How can you tame a horse' shouldn't be something you really need to know at this point, but far more relevant than breed for a beginner is training - don't buy a horse you have to tame & train, buy an older, well trained 'been there, done that' type for your first horse. Best to have at least one of you knowing what's what, rather than you & the horse both being 'beginners' - that can be like the blind leading the blind!