The video below explains a few basic safety measures you should take when moving into any new home. In addition, I always suggest my buyers change the locks as soon as possible after closing. Generally you will keep the same lock but the core will be changed, this is called a re-key. If you have a home warranty, also something I advocate for at least the first year of occupancy, you will pay only a minimal service fee and your home warranty will take care of the rest of the cost of the re-key.