I suggest a physical.

and ask a physical therapist on how to avoid muscle issues. i have a torn or inflammation muscle which still bugs me after 14 years.

Socks.

Foot pads.

plastic bags, including a few zip locs

20 feet of thin rope (laundry drying).

a roll of good fishing line. washers to make ends for fishing line.

vitamins: magnesium, zinc, D, C

a knife, a scissors

leather jacket

hooded sweatshirt

a large yellow handkerchief

dictionary

extra battery source

you may need to buy a new phone battery charger or 2

map

binoculars

get a crash course on infantry tactics from National Guards

crash course on first aid

ear plugs

double check everything here with the Guard officer

some gestures are a bit different in some countries. example in egypt, the gesture for finished as i am shopping or getting my booster shot

vaccines

dusseldorf airport is common for transfers. like a bowl of spaghetti. not too logical

laminated copy of passports, email, du password, phone numbers

copy of vaccines including corona

pcr test probably

rain, snow , cold

patience