I can't see your photo No Philadelphia minted pennies have ever carried a mint mark. The missing E is probably due to a grease/debris filled die. What is the date on your coin?
Don't let it get you down. A lot of us are slow on the learning curve, too. Welcome to CT. Keep on looking, posting, and asking. After looking at your photos, I stand by my first answer.
(You)... I really will read before I post. maybe.... sometimes... meah... who am I kidding... I might. lol
Welcome to CT! Filled die, pretty common. Most people don't collect them unless a lot of the design is missing, like this one: