At what age can I start training 2 puppies?

We rescued 2 little bitty puppies a few weeks ago from a man who couldn't take care of them (don't know what happened to the mama). They are 4 1/2 weeks old (will be 5 weeks this coming sunday). The smallest boy is very sweet & somewhat submissive. His brother, a tad bit bigger, is the dominant one. He growls about 90% of the time when they play and acts so vicious. He even snapped at me yesterday when I tried to separate them. Other than that he's as sweet as he can be & hasn't snapped since. I read that when they do stuff like that you can push them onto their side & hold them there until they are being still. I've done it every time & it seems to make him so mad but he does eventually calm down and I let him back up. Should I stop doing this? But back to my question: @ what age can I start basic training them? And any advice on training 2 puppies? I know I'm supposed to train them separately as well as crate train them separately. How can I positively correct the growling and meanness when they play? Thanks guys! Also, before it's mentioned, they've seen a vet & are healthy. We took them in @ 3 wks old & gave them their 1st dewormer and they will be getting it again next week & then 4 more times after that. They are also going for their 1st shots on the 18th.Meant to type "a few DAYS ago" not weeks. We got them when they were a day shy of being 3 wks. So we've had them almost 2 wks now

The sooner you start training a dog, the better. The best age to start training a dog is when they are about 6 months old. The growling and biting is completely normal for a dog of that age. Just like baby humans, baby dogs need to play too. When you start training them, it is best to train them separately, so they won't get distracted. The biting and growling is normal for any dog that is that young.

If you use food rewards and keep sessions short you can start now.i.e. lift treat up, puppy sits - you feed and say sit...There is plenty of information on the net on how to.Normally the only reason to delay is because they are with mum. Young puppies can learn basics including come and heel with no issues.In the 'old days' training was delayed until 6 months because methods were so harsh that young pups couldn't tolerate them.