Raspberry Pi GPIO Multiple Sensor

Hi, I’m trying to use Home Assistant with Raspberry Pi 3B+ for a final project, and a beginner.

For the (DIY level in miniature house, so I’d utilize GPIO) smart home system in my project, I’m using 2 type of sensor, which are PIR sensor (for security system) and Flame Detection Sensor Module (for fire detection).

To create security system and fire detection are there any additions or changes I should do for the parts? (I also have MQ-2 sensor and ultrasonic sensor HC-SR04)

Other than that, how to create configuration in yaml that handles multiple sensors (both of those I use) as well as displaying the sensor’s state in the Overview? I currently had this, but don’t know what to add next:

  - platform: rpi_gpio
      6: PIR Sensor
      12: Flame Sensor
    invert_logic: true
    bouncetime: 50
    pull_mode: UP

For the sensor’s output (planning to use buzzers), can it be done on relay switches or that there are other ways that wouldn’t involve relays (I’ve used relays but for other devices), like, directly connecting it to the sensors? (I don’t use breadboards)

Thanks for the help. Sorry for bad english.