A good way and easy way of boosting your WiFi signal inside your home is to purchase a WiFi extender which will extend the range of your WiFi signal so it reaches farther into your home and even outside.
If your WiFi router has the option to add external antennas then adding some antennas or stronger antennas can help boost the WiFi signal from your router.
Also try placing the WiFi router on a high shelf or mount it higher up on the wall and that usually helps improve the WiFi signal strength.