One day at a time. Dogs will pickup the concepts differently. Keeping it fun and positive, its what promotes drive and love to please.
Only give commands that you are willing to enforce. There will be good days and not so good of days. Always end a training session with fun and excitement.
Sounds like your doing well and pups are coming along.
Solid advice here ^^^.
I would also add, don't get too hung up on the retrieving...either the desire, or the chewing, or enthusiasm. They are still so young that none of it really means a whole lot at this stage, especially if you're going to force fetch later down the road. Biggest thing right now is forming that bond between trainer and trainee. You need to nurture and reinforce the dogs' focus on you, more than anything. Retrieving is in there... They're bred for it... It'll come. But the foundational, relationship "skills" that you form now will last their lifetimes and will influence the outcome of every single concept and command you try to teach.
That being said, wings and feathers are fun. Puppies should have fun. So keep doing what you're doing!
A couple more things I just thought of: If you haven't bought retrieving dummies (bumpers) yet, the 2" vs 3" is definitely something to consider. I own almost entirely 2" (diameter) bumpers, but if I were starting over I would probably go with 3" instead. I think the 3" bumpers do a better job promoting good mouth habits because the dog has more difficulty chewing it, rolling it around, repositioning in their mouth, etc. Also, little things like "place" training and hand signals (casts) can be started right now even at just 9-10 weeks old. Pieces of dog kibble work great as treats. Hand signals are easy... imagine a baseball infield... have the pup sit at the pitcher's mound, and place an empty bowl at each base... start with just 1st and 3rd to simplify (left and right overs) and only put them 5-10 feet from the pup... walk to each bowl, reach down and pretend to place food into each one, but you're only going to drop the food into ONE of the bowls... give an "over" cast to that bowl... pup goes the correct direction, pup gets a treat. Boom. Hand signals taught and pup has fun/receives treat. The sooner the pup LEARNS what these various commands mean, the easier and more confident you can be making corrections later during formal training.