How to fix a car that won't start?

My Audi A4 won't start, what could be the problem and how can I fix it?

First, check the battery to make sure it is fully charged. If the battery is fine, then it could be an issue with the starter or the alternator. It's best to take your car to a licensed mechanic to diagnose and fix the problem.

Have you recently run out of gas? If so, try refueling the vehicle. If that doesn't work, it could be a faulty fuel pump. Again, it's best to take it to a mechanic for proper diagnosis and repair.