Puppy only interested in environment / extremely distracted

I just got my standard poodle puppy 10 days ago at 8 weeks old. We are doing great with potty training and getting better on biting etc. We have enrolled in puppy class and so far have had one private session with the trainer and one regular puppy class (just yesterday). The breeder has advised strongly to only feed his kibble, no treats, as he has had trouble with dogs refusing food / almost starving themselves in the past (I think this concerned the mother and his sister from another litter).

I am worried about him being extremely distracted basically as soon as we leave the house, even for potty breaks in the yard. His nose is on the ground sniffing constantly and I am having a really hard time catching his attention at all. Obviously there was no chance of him focusing on me in puppy class. The trainer strongly advised to give higher value treats but had no other recommendations.

Do you have any recommendations on what I should try? This is my first dog, and I specifically wished for an easy to train puppy from the breeder :-(. I have read lots of books to prepare before he arrived, but none of them say what to do if the puppy refuses to pay any attention at all. I am trying my best but scared that he will grow up to be very badly behaved. Any help would be greatly appreciated.

PS: please excuse my english, it is not my first language