Conecting flight

what do I have to do exaclty to be on time on terminal 1 and be able
to take my second flight to athens...

Pray. Pray hard. That will be a very tight connection, even if your flight arrives on time.. Deplane and walk to passport control. Cross your fingers that the lines aren't long.Then collect your bags from the luggage carousel. Cross your fingers that luggage unloading isn't delayed or your bags arent the last ones to appear. Exit through the nothing to declare Cusoms doors ( assuming you have nothing to declare). Take the CDGVAL shuttle to terminal 1. Check in with your airline and check your bags. Pass through security. Assuming you are headed to a Schengen zone airport, you won't have to go through passport control again. Then go to your gate. Keep in mind that many airlines have a check in cut off time of an hour or more before the flight.

Best of luck.

Sorry to break the news... but you have a bad connection scenario, because you need to get to terminal 1 before bag checking ends, so at 11.15 latest I guess (check this!). This leaves you 1.5 hours to
- get off plane, get through the border, get luggage: hopefully less than one hour because you have a EU passport
- go to Terminal 1 check-in counter using CDGVAL train: 25-30 min from terminal 2E

You counted correctly: there is no spare time at all - a 15 minute delay on the first plane and it's over. Could you book a later flight? Can you cancel your accommodation that night if you are stuck in Paris?

If you can reduce luggage to carry on only that complies to Aegian Air restrictions, you can gain time.

This is not a connection; it is two separate flights. Flight insurance will not pay if you miss the flight. Because you will have to go through immigration on arrival you may well miss the flight. We were through in 15 minutes a couple of weeks ago and then waiting another 15 for luggage -- but that is best case scenario; we have waited over an hour in immigration in the past. You might make this if everything goes your way; you have a fair chance of not making it, so have a plan B.

CDG is not the place to attempt a 2+30 ground time between separate flights. It´s a roll of the dice.

As others have said, this isn't a connection. You are arriving at CDG Terminal 2 on one airline, then you have a ticket to depart Terminal 1 on another one.

Considering if you were starting in Paris that morning, the advice would be to be at Terminal 1 at 10:15 for a 12:15 flight within Europe, I think it's highly doubtful you'll make the Greece-bound flight. If your arriving flight is on time, hopefully you could be disembarked by 10 am or so, but you still have to walk to immigration control (which in itself can be a long walk), wait in line and go through immigration control, then *wait for your luggage to arrive *then find your way from Terminal 2 to Terminal 1, which is not in the same area at all.

My advice would be to purchase a new ticket to Greece for much later in the afternoon.

I really don’t even think it's a roll of the dice. There is too little time between flights and the fact that the second flight is from Terminal 1 really puts the kibosh on the whole thing.

When you miss a flight, you are considered a no-show. This automatically cancels any other flights on the same ticket. If you have a return flight from Greece on this ticket, it will be canceled. To be safe, you should pay the change fees to get a later flight, or buy a new ticket to Greece. Third choice is to pay for a walk-up ticket at the counter if you arrive too late for check in.