Both my dogs are getting neutered on Friday and I am so worried that something might go wrong, these are my children and when they get sick or anything I worry.:confused:

They should be fine. Neutering has become a routine procedure.
Make sure you follow all the vets pre surgery things such as no food and water prior to

When my dog got cancer at 11 years old I was told that pets should be spayed or neutered by the time they turn 7 to be healthier.

My cats sailed through the neutering process. When I brought Thomas Jefferson home, he immediately went to his food bowl and acted like nothing had happened. When Little Debbie came home after an overnight spaying, she was a little quiet but the next day was back to her normal bossy self.

Like Nohelp said, the neutering surgeries are so routine now that complications are rare and the animal has no bad reaction.

Ruth while there are no guarantees that nothing will go wrong. Your dogs have a much better chance at having a better life being neutered. Unneutered dogs will run out into traffic, runaway, chew through fences etc... to get to a female in heat, also unneutered males tend to be more aggressive. There are also the cancers issues to worry about.
Relax you are doing what is best for your babies.
I will say that I was told that dogs should be altered by their first birthday or heat, my neighbor said that her vet wants to wait until her puppy is 2. Different vets different opinions.
I personally have never known an animal that has died as a result of altering.