Well if your puppy is a beagle I think you are a very lucky man, because I have had first hand experience of both breeds. I grew up with a wonderful beagle called Alfie, who sadly got PTS at the age of 15.5 a few weeks ago. He was a very stubborn dog and we failed msierably with training as back in those days it was advised that the only way to train was by choke collars and not be rewarding dogs for good behaviour. Alfie was 100% food driven and so training with treats would have worked well. He was a very easy going dog - pretty lazy which we were not expecting (but fitted in well to our family) and was always good around children and was overall a great family pet.
Now we have Barney a cocker, and he did get to know Alfie a little before he died and apart from the difference in how they looked they are both is mischevious as each other.
I strongly believe that dogs, like children respond to the environment they are bought up in and I am sure you will have a wonderful life with Molly.
Rachel xxx