What do I train or work on to complete the German Armed Forces Proficiency Badge? What is the hardest part of the events?

SPC(P) (Join to see) make sure that you get the most up to date list of events (they change them all the time), and just train for those. you will have to swim, ruck, shoot a 9mm pistol, do some running and pull ups and whatever else is on the list these days

Swimming and tucking get a lot of people. A lot of people don't shoot with pistols much either, so that can be challenging.

Make a plan to:
Swim at least 2 times per week. Story, I could not make the shot put so I had to do the alternate event.
Run 2 times per week. We had an LT who bolo the 5K run.
Short Ruck March 1 time per week. Don't over train.
Bonus if you take the test fresh after a regular Army pistol range. I was very rusty at the range.

Good luck.