How do I build a competition-ready line following robot?

So I have some knowledge of Arduino and previously built a simple line-following robot using an Arduino, basic IR sensors, slow motors, and caster wheels. Honestly, it was very basic and nowhere near competition level.

Now, I want some advice on how to design and build a line-following robot for competitions. For example, regarding sensors—should I use an array of IR sensors this time, or are there better options? Also, would it make sense to switch to something like the ESP32 instead of Arduino?

Any suggestions or guidance would really help me a lot since I’m still a beginner.