Giving a valid delivery address ensures that you get your purchase on time. Here are a few tips that may help you enter it properly:
• Provide the house/building and apartment number if applicable
• Provide only relevant info in the corresponding fields, so the shipping label is easy to read
If you're not sure about the address or postcode, you can look them up on the website of your national postal service. FYI, check the links below, they might be helpful here:
As for the language, it's okay if you select either English or your mother tongue.