Your kid just woke you up and said, "I don't feel good." Would you lift his pajama top, look at him and say, "nothing looks amiss" and have him pee and go back to bed, or would you ask a few questions?

The CEL has just told you something is wrong. You can either guess about it and spend lots of time and money raising your frustration level, or you can ask it questions by plugging in a code reader and see what the codes tell you.

FWIW, a flashing CEL is bad, it typically means a serious misfire is occurring, and after that the car should run really poorly as the ECU will shut down one or more cylinders (they will reset on the next engine stop/start cycle).

If you don't want to buy a basic code reader, then get to an autozone (if you're not in California) and have them read the codes (for free). Write down the actual alphanumeric codes, don't just take their summary or translation (or worse, diagnosis). Then post them here and we'll try to help you out.

There is really no alternative for reading codes, unless you just want to start replacing things.

Good luck.