The first few days after your kitten arrives will be spent getting them settled in. There are a number of things you can do to help them get comfortable and used to their surroundings.
It's usually best to keep them in one room of the house for the first week, to allow them to become familiar with this space before exploring the rest of the house. The first thing you'll need to do is place a bed down for them - your kitten will need somewhere to retreat to if they are feeling overwhelmed, so a bed or a padded crate will give them a space that is entirely their own. You should also equip the room with everything they'll need day to day, such as water and food bowls, litter tray and a scratching post.
Let them explore their new space straight away, first with you in the room and then without, so that they can get used to your presence and settle into their new home. If you have other pets, introduce them slowly by giving them each other's toys to smell before meeting, to get them used to each other!