Proper socialisation with other people and other animals is very important for dogs and this should start early in life.
We would certainly recommend booking on to a local behavioural course: proper advice and a good start will really help to reduce future issues.
It is important to not suddenly change the food for dogs once you collect them.
Dogs cannot tolerate sudden food changes as this can cause diarrhoea.
Often food is provided from the breeder to provide a gradual transition (5-7 days) onto the food that you want to feed your new puppy for the long term.
Don’t expect your puppy to be toilet trained on collection. This takes time, patience and training.
Many puppies are not fully trained until 6 months old and even after this, accidents can still happen.