You have lots of good advice, and some not so good advice. Reputable breeders don’t let puppies go at 6 weeks. Crate train. Crate by your bed, get up when she whimpers, take her out, take her to the pee area on leash, stand there til she pees, say “go pee” or something consistently as she pees, no playing, back in crate. Maybe twice a night, then hopefully to once a night soon. She is too young to hold it very long.
Then during the day she should be contained to a small area — I like ex-pens to make a spot maybe 8 x 10 ft or so. Take her out to pee often, using leash, same spot, same words. By 12 weeks or so give her a bigger area, but always put her back in the small area when you can’t keep an eagle eye on her.
Also, lots of play time with ball, tug toy, clicker training to respond to name, sit, etc. This will give her mental and physical exercise.
Puppies are a big job and require dedication and management and a plan to train. Go online and watch some videos — Google Emily Larlham, dogmantics.com, great place to start.
Crate training is the way to go. Dogs will not mess where they sleep. The crate is her safety zone. You should also get a raised platform and place train her for when she is not in the crate. Mike Stewart of Wildrose Kennel wrote a great training book for training a retriever. Much of the book deals with hunting but the first part of hunting training is discipline. Check out uklabs.com.
When a pup is young, bedroom crating is fine. But as the pup ages, its important to begin some separation. For example, when my pup hit around 12 weeks, a second crate was added- in the basement during the day with my other dogs. A dog that is constantly crated near its owner is a candidate for severe separation anxiety.
Clicker training shouldn't be done unless you've done it before, or its part of a class. There's a lot of nuance in clicker training.
I completely agree with Old_Grouch except that twice a night is not often enough at this age.
The”formula”for how often the puppy needs to be let out of its crate at night to relieve itself is: 1 Month = 1 Hour. That means at the age of 1 month it can only hold it for 1 hour. At 6 weeks it has to go every 1.5 hours. And so on.
You need to put the crate next to your bed and take it out every 1.5 hours now, at the age of 2 months every 2 hours, at 3 months every 3 hours. I know this is difficult but it is an investment in the dog’s and your future. The puppy will cry and whimper when it has to go out and you must respond right away. If it waits longer than this formula you can wait for the cry/whimper before taking it out.
This accomplishes 2 things. First it housebreaks the puppy. Second, because the pup senses that you are responsive to its needs it builds a bond of trust that lasts for its entire life.