Such a trip can be a major culture and internal system shock and if not careful the dramatic changes can leave one not feeling that well for a train trip over extended distances. Food and wine are good healers, however. And tea! Europeans are tea drinkers and even on a train, the piping hot tea is soothing even on a humid summer day.
For safety bring your own food or purchase items from supermarkets at extended stops in larger cities if you have the opportunity.
Try to enjoy sitting and visiting with some new friends–trains in places like Russia and Bulgaria will do that for you. While some Westerners lock themselves away in a private sleeper berth, you might like to “meet the locals” during the daytime. It’s a great way to explore the language and culture, too.
Pepsi has been in Eastern Europe (long before Coca Cola) since 1959, introduced to Nikita Khrushchev at a taste test booth at a Moscow fair. Sales were halted after the Gary Powers spy plane incident but resumed after Richard Nixon became the US President. Pepsi was the first Western consumer product to be produced and sold in the former Soviet Union and a brand every Russian has grown up with. Since Russia controlled Eastern Europe, Pepsi is known all over these parts.
Most soft drinks in Russia, etc, don’t use the word “Diet Cola” as it has a very negative connotation, instead marketing a “Light” version (about 15 calories with low sugar).
Eastern Europeans are no strangers to Fanta, either. Fanta has been around since the early 1970’s.
Here is the Cyrillic spelling for several popular soft drinks found in Eastern Europe:
Кока Кола (Coca Cola)
Of course such terms are “cognates” (words borrowed from another language) and more and more, Western products tend to keep the English spelling of their brands as they become known internationally.