Perservere, it will be worth it! Keep a toy/chew handy so when he tries to mouth/chew on you/something he shouldn't, you give him that instead. He will get the idea. When our latest licked hands instead of nibbling, we said kisses, good girl. Then when she went near hands, we'd say kisses, & she would lick & get a treat. Soon stopped mouthing & biting.
Keep treats to reward good behaviour.
Don't just say no. It doesn't mean anything. Give a command. i.e. If jumping up - no, get down. And gently push him down. Etc.
Second the crate & playpen. You can get a safe break. We put a baby gate on the kitchen door.
Look up some training methods to get a head start on puppy classes & start building a bond so pup will want to do things with you. Treats work, find his favourites. Cheese, carrot, apple, bread/toast in cruton size bits. Chop up cocktail sausages - i could get 15-20 treats out of 1 cocktail sausage.
They all need effort put in but you will create a fantastic adult dog who will be a well loved part of the family.