Puppies like chewing everything so you should keep things out of reach.
Puppy playing with rope or cord can strangle itself.
They also can choke on small things and eat inedible things.
Electrical wires are very dangerous for puppies because puppies can chew
them and be electrocuted, so you should keep out of reach wires.
All chemicals products, cleaning products and also don't forget about agrochemicals for a garden should be kept in locked cupboards.
Some plants can be very poisonous for dogs, for instance, even one drop of euphorbia juice could kill a puppy.
Heavy and unstable furniture can fell down and hurt your puppy.
Unsupervised puppies should not have access to swimming pools because they can drown easily.
Take care of your puppy, as the saying goes, "you become responsible, forever, for what you have tamed".