Everything you need for a smooth solo trip to Durrës. Short version: you are cleared to go. Your Ukrainian passport and your Dutch permit each get you in, so the rest is just a couple of documents to carry.
Entry rights
Two independent rules both let you into Albania without a visa, and both apply to you, so one is a backup for the other:
Take your Ukrainian passport and the physical Dutch permit card. The permit card is what lets you back into the Netherlands, so it is not optional.
Departure · Netherlands
Dutch border police (the Marechaussee) sometimes stop a person under 18 who is travelling without both parents and ask to see written permission. The airline can ask at the gate too. It is routine, and it is there to keep young travellers safe.
Your parents are preparing the consent letter for exactly this. Keep it with your passport where you can reach it quickly.
The consent letter
Because you travel without your parents, carry a short letter signed by both parents saying they permit this trip. It does not have to be notarized:
Both parents sign by hand, write it in English, and attach copies of both parents' passports plus a phone number they can be reached on during your trip.
Your hotel
Good news from the hotel's own rules: there is no minimum check-in age, so you can check in by yourself. Keep your booking confirmation on your phone and printed as a backup.
Booking & payment
Booking.com allows you to make and pay for a reservation from age 16, so the booking you made is valid. At the villa you can settle by card or in cash. If the rate is refundable, even better, since it keeps your options open.
The flight
At 17 you travel as a regular adult passenger. The "unaccompanied minor" service ends years earlier, so you do not need it. Just glance at your airline's young-traveller page once before the day, in case they have a small form of their own.
Pack this
Rules can change, so confirm the details with your airline before you fly, and if anything is unclear, an Albanian embassy can give the final word. Prepared with love. Have an amazing trip to the Adriatic.