Hi and welcome to BPO!! I'm Andi mom to Koby (great dane). Owning a great dane is AWESOME! Koby is so gentle and a huge cuddle bug! BUT, and there's always a but.... I have to vacuum daily because they shed like crazy! Not like furballs floating everywhere but little eyelash like hairs that get into everything, clothes (itchy), drawers, walls, furniture. There's even times I get silverware and plates out to eat and I'm brushing fur off them! They also drool when they drink or eat so there will be lots of kitchen floor cleaning, I swear after Koby walks away from his water dish a gallon of water comes out of his mouth. I also frequently have to use that Magic Eraser to get dried goobers off the walls, windows and doors because they do fling nastys when they shake their heads. They can also be destructive. A 150+ lbs. dog chewing on furniture or walls can cause a ton of damage. I've seen pictures of sofas that have been destroyed, not just a corner, but the whole thing! Koby once came in from outside, slipped on our kitchen floor and his paw went through the wall, we had a big hole in our wall for awhile before we patched it up! We also no longer have grass in our backyard, from Koby playing and tearing up chunks of grass/dirt when he's running around.
I'm not trying to scare you from getting a great dane, because they are a great breed. After getting Koby I knew I would never be without a great dane, they are truly gentle giants! I just wanted to let you know that whenever you bring a giant breed into your home, your life will change, and there will be certain things you'll have to deal with. Since your still living with your parents this is something they would have to be willing to deal with, the fur, goobers, drool, dirt yard, and maybe even some household damage. Also like Julie said the Vet bills are higher and the food will also cost more.
Good luck, you're doing a great thing by researching the breed and getting to know them a bit better before bring one into your home! Once again welcome to BPO!