Dogs enjoy their treats and toys....
It can be a trading game with some dogs, with others you can just give a 'drop' or 'leave' command, or even just take from them.
All dogs are different and you just have to master what suits you and them with any issues that may arise.
My advise be in control and don't let these situation get too bad, try different things.. I remember as a puppy Oakley used to bite the lead on a walk and I thought it was a nightmare, but consistancy and me being more relaxed and in control, and it just stopped, they are learning and you are too, please don't be too hard on yourself, you will master what works for you both .... these are all thing we all go through with our puppies or dogs and still things pop up and surprise us on a weekly basis, I bet even breeders who are around dogs 24-7 get shocked by dog behaviour now and again, xxxxx