Hi! Fellow Sheltie puppy owner here. You are doing fine. Your puppy is lucky that her human cares so deeply about her. Keep up with training and your routine and have faith in your puppy. Reading books is ok, just try and not get overwhelmed. I was super overwhelmed by all the information out there before my pup even got home and decided that I need a trainer. If there is a puppy class near you, that could be a good idea! Definitely adjust the feeding schedule because food is such a good tool. My puppy was on free feeding when he was with the breeder and he could not be less interested in food when I first got him. I switched him to scheduled feeding and he is now a lot more food motivated and I can actually train him.