Hello, and welcome to CoinTalk! Feel free to post a picture to help us. The lack of a mint mark means that it was minted in Philadelphia. The only time a P mint mark was added to a Lincoln cent was in 2017 to commemorate the Philadelphia mint's 225th anniversary. As for the lack of an E, I suspect that it is from a grease-filled die, which carries no premium as it is quite common. For these reasons, I would suspect that your penny is not an error coin. However, you should post a picture of both of the coin's faces so that we can verify.
