Driving for Uber in Munich

Germany has strict regulations for taxi operators - and Uber falls under these.
That makes it very difficult to use the USA business model and therefore Uber operates only very few big German cities so far (and is still small even there). Luckily for you, Munich is among them.
First of all, taxi drivers need a special driving license and permit. To get this requires a few months of lessons and trainings at a cost of several thousand Euros (on top of a valid German, not USA, driving license). You also need to be able to converse with the passengers in German.
Secondly, Uber drivers here are employees and the cars are provided by the company. Your intended method of driving your own car would not work with Uber - but it may work if you are a self-employed taxi driver (which many are), after fitting the obligatory taxameter and taxi sign to the car.
Thirdly, to do any of this you need a visa allowing work. As a non-EU-ciitizen, you'll have problems getting a work permit on your own merits for jobs that locals from the EU can do. I assume taxi driving is among those. Thus your best bet is probably a family reunion or similar visa that, as a side benefit, includes free acess to the labour market. To get this, your wife needs to get a stable (and well paid) job first and you join her as dependent
Last not least, taxi driving is a typical student part-time job and, as such, not greatly paid. If you do it full time, you can probably survive, but won't get rich. Taxi fees are also regulated (by law) and Uber's apps disallowed, so there is no possibility for competitive advantage.
Altogether, I think, with your background you are better off doing other jobs.

In addition to what Beppi wrote, one can drive a noraml car with a US license for up to 6 months or up to a year if the time they will be in Germany is definitely limited to a max of 1 year. Then one has to get a German driver’s license which can take some time and a few thousand euros. A number of States have a full or partial reciprocal agreement so that one can simple exchange their US license for a German one - but California is unfortunately not one of them. And to be a taxi driver one needs an additional level of competency.

And I have to second Beppi’s other comments about the situation with Uber in Germany and the problematic of a US citizen working in Germany. On the plus side, US citizens are allowed to come to Germany and look for a job without getting a job seekers visa. The time limit for this would be 90 days in Schengen. What one cannot do is to actually move and stay longer without work. Thus before making such a move, you might want to come alone and see if you can manage everything before making the commitment to move your family.

No mention of Uber but the following link to the US embassy in Germany gives lots of important information about getting licensed.

https://de.usembassy.gov/u-s-citizen-se … n-germany/