Need help setting up home Wi-Fi network and security

I'm looking for someone experienced to help me set up a reliable Wi-Fi network at my home. I want to ensure strong coverage throughout the house and proper security settings to protect my devices. Ideally, you can also assist with connecting smart home devices to the network. I prefer someone who can explain the setup clearly and provide tips for maintenance. The house is a two-story with some thick walls, so signal optimization is important.