The best way to introduce a new puppy to your family is to set up an area that is theirs. Playpens work really well for this as do collapsible crates.
Once you have set up the playpen/crate try not to move it around the house as this can confuse your new furbaby. The best place is somewhere where they can see you at most times and feel like part of the family without taking over the house.
Just like human babies puppies need to toilet after feeding/drinking/waking from a sleep. This means that preparedness is the key; carry or walk your puppy outside immediately after eating/drinking/waking up from a sleep and give the toileting command of your choice (some include “do you jobs” “do your wee” etc). Once your puppy urinates or defecates give praise immediately, try not to be to vigorous however as this may distract them from finishing.
While your puppy is in their playpen or crate ensure to provide newspaper or puppy training pads for them to toilet on. If they toilet inside the house say “no” firmly then pick up your puppy and take them outside to finish; giving the toileting command once outside and giving praise once toileting outside.
NEVER punish a puppy for toileting in the house if you have not caught them in the act. Dogs cannot associate the act with the punishment and this can cause an anxious puppy in the future.
You can use products that may help to encourage a puppy to use a particular spot outside or the puppy training pads inside