Some cheap security for your home.

6 inch deck screws. Replace your exterior door hinge screws, and strike plate screws with 6 inch deck screws. Drive 6 inch deck screws every 6 inches along the door frame. These screws will reach the wall studs framing your door. This distributes the force from someone attempting to kick in your door.

Purchase a reinforcement plate that covers the lock area of your doors. This greatly reinforces the weak are around the locks. Even steel entry doors benefit from this security plate.

It will not stop a determined attacker. It will slow them down and make a lot of noise, alerting you and giving you time to confront the threat. I may also force the attackers to choose a different entry point or a different victim.

For true entry denial a door barricades is easy to install. Will wear out a battering ram operator.

Also makes spreading the door frame to disengage the locks much more difficult.

One of my favorite "dead bolt" locks is installed by only drilling the inside of the door. Leave no trace on the outside. Used for securing the door only from indoors. Place one high and one low to add more reinforcement to the door.

Especially low where the force of the kicks are strongest.

All this leaves your windows as the only easy entry point. That takes time, makes noise, and broken glass cuts to injure and leave DNA.