Will be in Greece from May 18th-June 1st going to Santorini, Ios, Athens, Meteora, and Corfu! Let me know if you'd like to travel alongside!
5 stops in 13 days is going to feel very rushed. I suggest you eliminate at least one island. Corfu is in a completely different area than the others, and unless you fly there from Athens you will lose one full day in transit from Athens, plus the time it takes for you to return to the mainland from the other islands. Another full day will be lost going to and from Meteora and Athens.
I actually just redid my itinerary and I'll be staying until June 5th!
If you are going alone, your itinerary, sensible or not, is strictly up to you. If you actually are looking for a travel companion, you would need to tell people a lot more about yourself, and the reasons for your choices. For example, most first-timers to Greece look toward the Cyclades islands (Mykonos, Ios, Paros, Naxos, Santorini etc) because of the blue-white "holiday poster" architecture ... and they're also on roughly the same ferry route; much easier to link together. As BRotherLee says, Corfu and Meteora is waaaay out of the way, not connected to any of the others. Even with a longer trip-plan, most people need a compelling reason to go to either. I often find that people listing corfu have not looked at maps or a guidebook, but are enchanted by a picture of a single beach; similarly others are attracted by dramatic photos of a Meteora monastery on a pinnacle, but not aware of the transport and time issues. This may prove to be a very rewarding trip for you, but the logistics involved may discourage others from joining you.
I'm not just doing Greece I'm also doing Croatia, Italy, France, Spain, England. So that's why I'm doing a lot of Greece, going to Corfu and then taking the ferry to Bari - Dubrovnik. That's why I have expanded it all the way out there. But yes, a little about me, I'm 21 year old Canadian girl who's on her first backpacking trip to Europe. I enjoy nature, countryside, and cities. Not a HUGE hiker due to my asthma but like to explore as much as I can. I do like to drink and have fun. Live music is especially important to me and would like to experience as much music culture everywhere I can. On a pretty tight budget and would like to stay in hostels/couchsurfing.