These are the very first things you should do after buying a house (for obvious reasons):
1. Change locks. Spares could be floating around anywhere.
2. Hide an extra key in a lockbox. Thieves look under flower pots.
3. Reset the key codes for garage doors, gates, etc. The former owners might’ve trusted half the neighborhood.
4. Test fire and carbon monoxide detectors. Who knows when the last time was. Definitely install them if there are none.
5. Check the temperature on your water heater, especially if you have young ones, so it won’t accidentally scald. Manufacturers tend to set them high. (but the best temperature setting for hot water is 120 degrees).
6. Make sure motion lights and other security lights have working bulbs.
7. Put a fire extinguisher in the kitchen and each additional floor.