Alphaparents, since mixed breed dogs tend to obtain certain characteristics from their contributing breeds, none of which is predictable, it would be best to read up on both
breeds. This Section is intended as an overall, broad view of specific breeds.
Since your puppy came home prior to 8 weeks, there is a lot of learning that you will need to teach Jax that he did not obtain the benefit of learning from his siblings and Mother. Jax could have more Lab qualities than Aussie qualities, or vice versa. You can't possibly know that at this early stage.
I would suggest you visit our Behaviour Section as just about every issue known to puppyhood is covered in there. There are commonalities amongst all puppies, regardless of their breed.
You will find that most of us on The Daily Puppy believe in positive training methods. We have a few members who are behaviourists. We also have many members with a lifetime of experience with many different breeds who can offer support and advice. I suspect Nipping/Biting may be of interest to you, especially at this stage, along with concrete steps to housetraining, although you mentioned that was going well. There are also tips on crate training which could be helpful to you.
You are new to the site today, so please take a moment and have a look around. If in doubt about starting a thread, or asking a question, you can always PM one of the Mods (in blue) and we'll be happy to help.
Best wishes to you.