OMSI 2 comes with a manual, which can be accessed in the Steam page or by clicking on the following text: OMSI 2 Manual. The manual explains the main points needed to know to operate a bus so please read it.
For some reason, the manual is translated to English but the pictures are not. For the most part, you can understand the manual without understanding the text in the pictures. You can always read and view in-game what you are reading, but you have to change the text to English first. To do so, follow these instructions:
From the Start menu, click on "Optionen" which will prop the Option menu.
The first drop down menu for "Sprache" which will be in "DEU" for Dutch by default. Switch it to "ENG" for English.
Click the "Ok" button which is located at the bottom left corner.
Once you switch the language to English, the manual's text will make sense. You can also click on the following text: OMSI 2 Manual [EDIT] for an edited OMSI 2 manual with the pictures in English. This manual was edited by OMSI2.net personnel and is not the official edit of the manual.
That being said, there are several cultural differences between Germany and the United States so here are a few things to keep in mind as you read the manual:
Germany uses military time. After 12:00pm. just subtract 12 from the time and it'll give you the time. For example, 14 - 12 = 2 so 14:00 = 2:00pm. Another shortcut would be to sutract from the second digit of the time. So for 14:00, take 4 and subtract 2 so it'll be 2:00pm. Keep in mind that this only works up until 20:00 which is 8:00pm.
Germany uses the following date format: day, month and year. So if you type in "15.2.1997" that'll signify February 15, 1997.
New timetables begin at 4:00am and 5:00am. So if you are switching from timetable Mo-Fr to timetable Sa, then it won't take effect until Saturday at 4:00am or 5:00am.
Other game facts not covered by the manual:
The error messages are in German no matter what. I usually just click "ok" and hope that nothing changes. If the game crashes, then I force exit the game with the task manager and start again.