Here are some common German expressions and phrases that you should know:
Guten Morgen / Tag / Abend - Good morning/day / evening
Wie geht es dir? - How are you?
Mir geht es gut / schlecht - I'm doing well / poorly
Danke - Thank you
Bitte - Please / You're welcome
Ja / Nein - Yes / No
Entschuldigung - Excuse me / I'm sorry
Ich verstehe nicht - I don't understand
Ich spreche kein Deutsch - I don't speak German
Wie spät ist es? - What time is it?
Auf Wiedersehen - Goodbye
Bis später - See you later
Prost! - Cheers!
Alles Gute! - All the best!
Vielen Dank - Thank you very much
These are just a few examples of common German expressions and phrases. As you continue to learn the language, you will encounter many more that will be useful in different contexts.