You should check your passport expiration to make sure it stays current. Make copies of important documents in case you lose the originals and make sure you have all your travel documents in order.
Yes, you need a passport to travel to Europe.
Yes, typically you need a round trip ticket to travel to Europe, as most countries require proof of onward travel for entry.
Not a vista but you need a visa to travel to most of Europe from most of Africa.
A car.
Yes, a green card holder can travel to Europe, but they may need to obtain a visa depending on the specific country they plan to visit. It is recommended to check the visa requirements of the country they intend to travel to before making any arrangements.
No, you cannot travel within Europe using only your residence permit. You will need to carry your passport with you for travel within Europe.
No you can't travel to Europe by using your Green Card..For that you need a valid visa to enter into the European Countries. In case if you travel via Cruiseship then you need not want Visa it seems..You can check with the travel agencies before proceedings..
Yes, you should sign your passport before using it for travel.
As far as travel to Europe there are no health restrictions from the USA to Europe. They do want you to have medical insurance or medical travel insurance. The medical in most of Europe is modern and comparable to USA. If you are taking a pet, dog or cat, they must be certified by a Veterinarian.
Yes, you must sign your US passport before using it for travel.
Southern Europe, specifically Italy.
No, you cannot travel to Europe without a passport.