I can deal with the AI pretty well. It's human players that give me trouble.
That's cool, and I hope you didn't think I was trying to be mean. It's a harsh lesson we all have to learn, you gotta guess once you get hit, and make sure you're not just staying still and taking things you don't have to.
Look at the animation for air hand, learn to recognize and run or jump or whatever you need to do to avoid it since it's unblockable.
Ground hand is crazy fast but very negative on block, so anytime you're on the ground you gotta block that move. So once you block it, you need to recognize that as fast as possible then take your turn to so Shinnok can't do it again.
Every time you get hit by either one of those moves you're in the same situation: on the ground fullscreen from Necromancer Shinnok, and you need to know what to do there. What are his Options? What are yours?
His immediate options are air unblockable hand, ground hand, and flick. Your immediate options are wakeup attack, move (run and/or jump), and delayed wakeup. These are all the things you should be doing in training mode. Learn every move you're losing to and how to beat it. Then recognize every bad situation you get in and how to turn it to your advantage or weather the storm until it's your turn.
This is fighting games, you got hit so you have to guess, and every time you do make a mental note to track the patterns in your opponent so you're more likely to guess right next time. It takes years to develop this skill and it's the most important one for fighting games. It's why we call them reads instead of guesses when the great players do it.