rather than say no, teach him and reward what you DO want him to do.
peeing on floors is a HUMAN error not a puppy error. he's too young to have nay idea on that front. Take him outside often, praise/reward and supervise more closely in the house.
Chewing - interrupt and redirect to an appropriate chew toy. Have plenty of appropriate chews available but switch them out so they are nto all out all the time ("new" is always funner).
Puppy nipping is VERY normal and you may have even more issues with this as he was removed from teh litter too early (generally best to wait til 8 weeks - it may not seem like much of a difference but the 6-8 weeks period they learn A LOT from the other puppies in teh litter about nipping and dog-behaviour). There are a few ways to work on this. One is to yelp (high pitch) and trun around so they can't "get" to you. It will take time and MANY MANY weeks of consistent repetition to get thru this though. You can also just redirect to an appropriate chew.
here is a thread on puppy biting/nipping. alternatively you can use the search function as it's one of the most common issues with puppies Puppy biting!
I HIGHLY recommend puppy classes. They are FUN and great for tips on training and basic puppy issues plus great for socialization in a safe environment (the period before 12 weeks is the most critical socialization period but unfortunately also when they are more at risk as they are nto fully immunized, so important to find safe places and ways to socialize to people, textures, sounds, objects, dogs, etc.)