Europe 9/8 - 10/1 (Greece, Barcelona, Ibiza, London)

Hey there, I am a male from the US in my 30's getting ready to make my first solo trip to Europe. I visited once before right out of college and can't wait to return. I will be flying into Athens on 9/8 and flying out of London on 10/1. Everything else in between is flexible. I would like to spend time in Athens and the Greek islands for about a week, briefly visit Rome, explore the craziness of Barcelona and Ibiza....I so have to check out the foam party.....for about a week and finish my trip in England for about a week. I timed my trip to be able to catch the NFL game in London on 9/29. I have built in lots of flexibility and am open to suggestions and ideas. I would love to meet up with other travelers for drinks, meals, stories or travel buddies. Let me know if you are interested. I hear that traveling solo will change your life and give you stories and friends for many years to come. Michael