The Condor carry on bag policy is actually pretty straightforward. They allow one carry on bag per passenger, with a maximum weight of 8 kg (that's about 17.6 pounds for our non-metric friends). The bag should also fit in the overhead compartment or under the seat in front of you, which is pretty standard for most airlines.
Now, you might be wondering, what about size? Well, Condor specifies that the carry on bag should not exceed 55 x 40 x 20 cm (that's about 21.6 x 15.7 x 7.9 inches) in size. That's roughly the size of a large backpack or a small suitcase, so you should be able to fit all your essentials in there. Think of it like packing a weekend getaway bag, but for a shorter trip!
It's also worth noting that Condor has a strict policy when it comes to carry on bags. They don't allow any bags that are too large or too heavy, so make sure to check your bag's dimensions and weight before your flight. You don't want to be that person who has to gate check their bag at the last minute, do you?
Condor Handgepäck - Maße und Gepäckbestimmungen