1. Entry restriction: You must be vaccinated to enter from nonEU countries (Vaccation must be in the approved list)
2. Most restaraunt/bars/outdoor gatherings are either 2G/3G. The bahn is 3g (so testing as well). Nearly everything else is 2G. This includes the food hall in the airport. Enforcement is at entry. You must show your personal|lebenlingsausweiss and your coronapass. (identity license, and vacination evidence.. CDC vaccine card can work.. but get it converted and your life will be easy)
2g = genesen, geimpfung / recovered, vacced 3g = 2g+ gettestet
3. Many restaurants expect or require you to use Luca to participate in contact tracing. If that is not possible they do a manual collection of info.
These rules are even enforced at outdoor gatherings such as weihnachtmarkts.
Denmark/Coppenhagen: Only ate inside at one place. They only wanted to see my coronapass.