Hey, I just got a pekepoo from one of mall's petshopp a couple of weeks ago and he has been a complete handful, I need tips on these things if someone can help me,

a) How do I stop him from biting peoples legs,feet,hands,arms,and fingers?
b) What are the best potty training tips you can suggest me?
c) How do I stop the constint crying when I put him in his crate when I want to go to bed?
d) How do I calm him down when he gets into that super-hyper-puppy mode?