The first step when you suspect engine problems is to check your oil level. Other noises like ticking could be valve train issues and knocking could be bearings. If you suspect you're having engine trouble at all, have a mechanic look at your vehicle immediately. You shouldn't attempt to drive your vehicle if the oil light is on, temperature gauge is in the red area or you see smoke coming from the engine compartment or the tailpipe.
The engine light could be on for many reasons, again, it's always a good idea to have a mechanic have your car scanned. If your vehicle is running normal, it could be related to emission control equipment.
Regular maintenance should include having your oil changed regularly. In colder temperatures it is a good idea to let your engine warm up before you drive. When it's really cold outside it is even more important to let the oil warm up as it will also be cold and sluggish. Have your timing belt changed as per manufacturers schedule.
When you suspect you have engine issues it is helpful to keep track of exactly what is going on at the time to help the mechanic diagnose any issues.