Yes, I don't understand, lots of members list EKG findings on this forum, they should be interpreted by your doctor, and seen together with the clinical status.
There are limits for how high and wide the P wave (which represents atrial depolarization, the upper chambers contract) should be. A high or wide P wave may indicate an enlarged atrium because it takes longer time for the current to reach through it. The electrode "V1" is placed close to the right atrium, so current should move towards it (positive) and away from it (negative) as the impulse travels from right to left atrium, creating a so-called "biphasic" P wave in a normal EKG.
But EKG is very insensitive in evaluating the atrium. If your doctor suspects that your atrium is enlarged, he may consider referring you to an ultrasound of the heart. Jerry is right that an enlarged left atrium may be a risk factor for atrial fibrillation, so if you experience symptoms like irregular heart beats, dizziness, shortness of breath or palpitations, you must see a doctor.
The ST depression is another story. It may be a marker of a variety of heart diseases, and also some other diseases, but it may also be a normal finding. 0,05 MV is very little, the limit is usually 0,1 MV for it to be significant, but it must be seen together with the rest of your EKG and your clinical status. It should be evaluated by a doctor. We are not doctors. With age, many of us will develop EKG changes, but the doctor must decide if they warrant any further testing or they are just normal variants.
I hope your doctor didn't just dump the data on you.
I think it takes at least an echocardiogram to measure heart chamber sizes, e.g., enlargement or not. I guess that's why you have "possible left...". I don't know the "correct" numbers for the "P wave", but a missing or fibrillating P wave is associated with atrial fibrillation, which may be accompanied by an enlarged left atrium (which is my case). Don't take me to be saying you have AFib, that's for your doctor to diagnose.
Do you have an irregular and/or a fast (high) heart rate? These are also symptoms of AFib.