Whether "moin" is short for "Morgen" is ...debatable. A Wikipedia article goes into great lengths on the different variants of proposed etymology of the word. Other than being traced to "Morgen", it has also been connected to "moi" meaning "good" (moi'n Dag = guten Tag).

Read Intelligent Investor by Benjamin Graham.

Gotta understand how long-term investing works, how to create a portfolio with stocks, bonds and other stuff. And pick a strategy that you’re gonna stick with so you don’t panic during recessions and sell off your holdings, losing money as a result.

For example. If you have 100% stocks portfolio and no cash. And the recession hits. Stocks go down. You lose a job or have unexpected expenses. You need to tap into your savings. You’ll be forced to sell stocks at a terrible time.

The book will help you all future scenarios that can happen and how to be prepared for it.