I agree with VegasTriker that ability to charge devices with a USB charger that works on multiple voltages is ideal. Add a mix of outlet adapters, not sure where you are but I checked your profile and I think you are in Poland. You would probably be looking for adapters for UK, China, USA, etc. You could wait and buy adapters as you need them.
You might consider a dynohub and a USB charger that can convert that hub power to USB power. As you are riding and when your lights are off, you can put that extra power into a power bank for those times when you do not have a power supply for several days at a time. There are more USB charger options available in Europe than there are in my home country (USA), so I will not recommend a specific USB charger. Son dynohubs have the best reputation but are quite expensive. If you get a dynohub, do NOT submerge it in a stream crossing.
Some people prefer solar power over dynohubs, I have not had good luck with that but that is an option you may consider.
Bike touring, I almost never use a headlamp on the bike when I am touring. I have started to carry a light in my handlebar bag that I can strap onto the handlebar when necessary instead of installing a light on the bike. But for riding near my home, I am using dynohub powered headlights that are fitted to several of my bikes, the one that I would rely on if I was going to do a multi-year tour would be the B&M IQ-XS that is mounted on a bike.
I almost always have a battery powered taillight on for safety purposes. In countries where you can use flashing taillights, that may be a good idea. Where they are illegal, then a solid taillight makes sense. I have two battery powered taillights on my touring bikes, on one tour a light died from water ingress (rain) and corrosion, a spare came in handy. Your taillight if you have it on during the day should be energy efficient enough to last for a week without a charge since your ability to recharge it may be limited. Avoid the really bright ones that need to be charged every day.
If you also wanted a dyno powered taillight (solid on, not flashing), you wire the taillight to the headlight, thus that light would be turned on and off with your headlight. I suspect that the dyno powered lights would be turned off most of the time so you can charge batteries, but if you want such a taillight, I think the B&M Secula Plus that is seatpost or seatstay mounted is a very good choice.
You would want a good headlamp to wear on your head after sunset when camping. There are many available in Europe that are not sold in my country, thus I will not suggest a brand or model.
When touring, I want all of my electrical devices to be charged with USB power because I use a dynohub and USB charger for most or all of my power. Other electrics besides bike lighting include the headlamp (for my head), camera, cell phone, GPS, and possibly a UV water treatment device (Steripen). That said, I often use rechargeable AA and AAA batteries, but I have a charger for those batteries that is powered by USB.
After my last tour a year and a half ago (pre-Covid), I wrote up a summery of my electrical equipment and usage on a different forum. That trip was five weeks, if you are interested in reading that, it is at:
Electrics that I use for bike touring - what works for me.
Have a great trip.
ADDENDUM ADDED DEC 7, 2020
Above I suggested the B&M Secula for a taillight, but on second thought a B&M Top Light that is attached to the rack may make more sense.