Just wanted to provide a quick update (after about a week).
She is WAY WAY better now than she was before. There are still some problem habits that I'm hoping maybe some folks here can help with, but first the good news.
I use the prong collar STRICTLY for when we go for walks. Her pulling has almost completely subsided. The only time she pulls or stops abruptly is if she needs to pee or poop. Unfortunately I don't have the appropriate skills to make that a command yet, but if anybody has any tips that'll be awesome.
In the house, she comes almost 99% of the time when I call her and she is extremely receptive to commands (unfortunately she ONLY listens to me, my mom, and my dad, not anybody else which is somewhat troublesome). Outside, lets say we are playing fetch with a ball, she will come when she knows I have treats. I click, treat, praise and throw a party every single time and she's gotten pretty good. For some reason though she will either get tired or something because she'll after like 5 min just go sit under a tree and then lay down. My brother told me when she does this she wants to chase and run around and... well she does. I love when she does this (who wouldn't?) but it's not what I want her to do! at that time lol. If anybody has suggestions that will be great. She also will sometimes do this hilarious thing where she will take a stick AND the ball in her mouth and come with both lol. It's so freaking funny! I love it!!
Now for the bad:
She still jumps on people. I don't know how to make her not do this. I'm trying everything, ignoring her, whatever, nothing doing. She's been trained to be allowed on the couch, she jumps off when she sees me but I've seen pictures of other GSDs sleeping on couches and stuff and I'm not sure if I should even stop this habit. I kind of like her on the couch but not at expensive of being seen as a beta in the heirarchy.
When we are entering and leaving the house, maybe 25-50% of the time she waits for the humans to leave first or enter first before she does. The other times, she will just run out. I don't know how to stop this. This is extremely frustrating. Lets say my dad is going outside, she hears the door open and literally I swear out of nowhere she may be on the other side of the house, you blink and she's outside! Then she doesn't want to come inside lol. Even when you command her to sit or stay, nothing. This reminds me, she can Sit and Stay but she only Stays for very very short periods of time. I want to train her (inside at first) to be able to sit and stay for at least a few minutes, but I'm struggling. Does anybody have any pointers?
That's the major update for now! Thank you all for your help!