So cute!! It depends on what type of show the club is having. They have fun shows or fun classes at sanctioned shows. See what clubs are by you. There is a show in greenfield mass by Springfield. Not sure how far upstate you are. I consider where my girl lives upstate and that's Saratoga
But I also know you can go and meet people at shows and see who is willing to discuss and who may have a track so you can practice and others who help with tips and suggestions. IMO You should wait for dogs to be old enough to have pennhip tests which is two years old before heavy training and pulling. I know some who go of prelims and start at 18 months. Harness are expensive and custom fits are proper for heavy weight so they should finish growing. Or it can get costly.
You can get the pup used to a harness and dragging small items and learn the routine but not do crazy weight until the dog matures. Just my opinion.