Olive oil is the basis of the diet and many of the benefits appear to come from the good monounsaturated fats but also the polyphenols in the olive oil.
The high consumption of vegetables is a main characteristic of the Mediterranean diet. Greeks consume almost a pound of vegetables a day.
The Mediterranean diet is about real food. That does not mean one has to cook from scratch everyday but learning 2-3 basic dishes will greatly improve your diet.
When we look at the traditional Greek diet, the Greeks abstained from animal products about 200 days a year for religious reasons.
I often see in recommendations for healthy eating plenty of vegetable dishes but also quite a bit of meat.
Focus on whole, unprocessed foods. Base your meals around fresh fruits and vegetables, whole grains, legumes, nuts, seeds, and lean proteins.