It’s good that he does not bite – he certainly has potential to train more. Generally it is easier to train a bird when the wing feathers are trimmed. You can have this done by a professional at your Vet or a bird shop. Don’t worry – the feathers will grow back when he molts again. But training will go a lot better if he can’t keep flying away from you.
It is also better to train him before you let him have so much free access out of the cage. If he can be out all of the time anyway, he has no incentive to bond with you. If he depends on you to take him out to handle him, he will look forward to that contact. Basically too much freedom also makes a bird very hard to train.
I recommend that you read through these pages and you will learn more about his behavior, body language and how to work with him.
Pet Bird and Parrot Behavior
Teaching Your Bird
As far as diet goes, the Nutri-Berries are nutritionally balanced the same as a pellet, so he is getting complete nutrition with those. However, offering fruits, veggies and table foods is also good and helps him to have a more varied diet. Offer things more than once – sometimes it can take a bird a while to recognize something as a food.
This link here will help with some diet suggestions:
Bird Food Guide
Congratulations on your new bird!