If your engine is making a ticking noise, there are several possible causes. The most common cause is an exhaust leak. If you have an exhaust leak, it's important to get it fixed as soon as possible. An exhaust leak can cause your engine to run lean, which can lead to engine damage.
Another possible cause of a ticking noise is a lifter tick. This is caused by the lifters not being properly lubricated. If this is the case, you'll need to add oil to the lifters and then start the engine and let it run for a few minutes. If the noise goes away, then you know that was the problem.
If neither of these solutions fixes the problem, then it's likely that your engine has valvetrain damage. This could be due to worn out valves or rocker arms. In either case, you'll need to take your car to a mechanic and have them look at it so they can diagnose and fix the problem