I got Bella at 6 weeks, and everything went smooth as could be. I will wish you the same luck that we had.
I would give the same advice as others and say get some goats milk, I believe they have it canned at walmart. Puppy formulas are just not as good. Goats milk is as close to mama's milk that you can get. Also ditto the advice on the nutrical, I luckily have never had to use it with either of my babies, but I always had it on hand just in case.
I would also make sure he gets plenty of rest and stays warm. Good luck to you. Things should be ok!! Lets see some pics too.