A trip cancellation insurance can help you to get your money back in case you can't travel when you are sick with Covid19 or in case you have to quarantine due to Corona. In this case, you can claim your money back from travel insurance, a so-called Reisekostenrücktrittsversicherung. Make sure the insurance includes a Corona clause.
Please note that most insurers don't cover if a nation goes into lockdown and shuts all traveling down. You can usually travel to countries with high Corona prevalence for which Germany issued a travel warning or Reisewarnung without risking insurance coverage. No insurance pays if you cancel a trip because you personally think it's too risky because of the Corona situation.
I found it very useful to sign up with travel insurance that covers all trips in a given year so I don't have to think about insurance for each flight separately. Most insurances cover the flight price and hotels or other accommodation costs.
Please note that some but not all travel insurances cover the costs of hospital stays in another country. You might think about *international health insurance or Auslandskrankenversicherung to avoid high hospital bills from another country, especially outside the EU, which are not paid by your German health insurance.
HanseMerkur offers travel cancellation insurance for any number of trips per year starting at 47.- Euro per year. HanseMerkurs signup page is in English.
Compare travel insurance prices
The following German websites help you compare prices for travel insurance: