I would love to answer all your questions, but right now I'm watching son's of guns on Discovery. So I'll keep it simple
I think a 10/22 would be a fantastic choice for your first firearm. They are in my opinion, the most universal semi auto .22 lr rifle available. Accurate enough to have fun, and still keep good groups at reasonable yards. The removable mags are a plus. 10 shots for factory mags. 25 round butler creek steel lip mags are great to have fun with and work very well. Also alot of aftermarket mods that can increase accuracy, among other things. I however love mine just the way it is.
10/22's are VERY reliable when using decent ammo, and just keep it fairly clean and your all set.
I prefer it with iron sights, I enjoy the open sights. It makes it fun to point shoot, and do snap shooting with just the front sight, and then bring up the rear aligned with the front for precise shots with a traditional sight picture. You'll find that the sights are very good on a 10/22. And of the 3 that I have fired, none have needed adjustment, and all have shot straight to point of aim from the factory!
I understand your wanting to step up to a larger caliber, thinking it will give you the rush of shooting a "gun". But if you can find the joy of shooting in a .22lr (the precision, the slow even trigger pull, the enjoyment of firing a bullet from an explosive cartridge hitting your target, the smell and sound. it all comes together) you'll be able to responsibly, and truly appreciate the larger calibers. Based on your post. I'd say you sound like a smart and reasonable young man. I think you'll do fine with whatever you chose. But in the end, Everyone loves a .22lr... so I think thats your best starting point.
Practice is really just having fun. Getting good at shooting is like learning how to play an instrument. You eventually develop your own style, but there are many styles, and you can learn something from all of them.
10/22 and many many experimental shooting sessions... and continued Internet research and conversations, and you'll be feeling good.
Enjoy your new found hobby, and make sure to bring along some friends. Always do your best. And always stay safe