What is the best way to troubleshoot an Audi A2 engine that won't start?

I have a 2001 Audi A2 and the engine won't start. The battery is good and there is fuel in the tank. What could be causing this issue and how can I fix it?

Check the fuel pump and filter. Sometimes debris can clog them, preventing fuel from reaching the engine. Also, ensure the fuel injectors are functioning properly.

The ignition coil or spark plugs may be faulty. Have them checked and replaced if necessary. Also, check for any cracks or leaks in the ignition system.