Help in Coding of smart home

Recently i doing a project which is automatic lamps and fans.
In the project, i use 3 sensor, IR sensor to replace PIR motion sensor, light sensor and temperature sensor
When the IR sensor sense 'human' it will activate the lamps and fans.
The light intensity for the lamp will due to light intensity of the outdoor.
The brighter the outdoor, the dimmer the lamp.
The fan's speed control by the temperature.
The higher the temperature, the faster it rotates.

I using mplab ide 8.86 as my compiler and pic 16f877a

What is the question?

the question is i didn't know how to code

Start small. Flash an LED first
When you know how that works, things will fall into place.
Nigel's tutorials in asm...
Nigel's tutorials.. re-written in C. https://www.electro-tech-online.com/content/467-nigel-goodwin-s-tutorials-c.html

Part numbers for sensors? links to data sheets? Hard to offer much help when its like pulling teeth to get info from you.