Buy a welcome card and have the whole team sign it-put it on their desk/work station along with some company swag if you have some. Like a water bottle, note pad, t-shirt, etc. Buy the team lunch so they can all take a break and welcome the new person. Also-most important. Have a plan for training and write it down. Make sure someone is dedicated to giving them the one on one training. So often, we throw our newbies to the fire and then 6 months down the road complain that they aren’t “catching on”. The first two weeks are essential for training. Good luck!