The smart move is to set up your eSIM days before your flight, not at the gate. First check that your phone can use one. Most iPhones from the XS onward, plus recent Google Pixel, Samsung Galaxy, and other newer models, support eSIM. Also make sure the phone is carrier unlocked, or it may refuse the new plan.
After you buy a MegaEsim plan you get a QR code. Open your phone settings, add the eSIM, and scan it while you are on home WiFi. The profile downloads and waits quietly until you arrive. Do not delete your normal SIM. You keep your home number for calls and texts and let the eSIM handle data in the Netherlands.
Pick the plan that matches your trip length. A weekend in Amsterdam runs fine on the 3 GB for 15 days plan at $2.10. A longer two week visit through Rotterdam and Utrecht fits the 10 GB for 30 days plan at $5.99. Heavy users who stream and tether can grab the 50 GB for 30 days plan at $29.89.