Economic way from-Geneva to Haarlem-Nertherlands

Most economical way is to buy two train tickets. Try one of these options: Genève-Paris + Paris-Amsterdam or Genève-Frankfurt + Frankfurt-Amsterdam or Genève-Oberhausen + Oberhausen-Amsterdam

Your cheapest route would be to fly easyJet from Geneva to Amsterdam and take a train from the airport to Haarlem. Like all budget airlines, easyJet has strict luggage weight, size, and number limits. Pay attention to the check-in deadline. If you don't have a boarding pass in hand when the deadline arrives, your ticket will be worthless.

Thanks Ralph. for your suggestion. Hitchhiking is out of the list of possibilities.
We thought about a train or to tent a car. There are special buses that take people in a tour around Europe. We are not familiar with the right train to take. We can buy the tickets at the station at the last moment or in advanced from USA. That is our big question. Today we thought that perhaps we should rent a car in Geneva and drive all the way to The Netherlands were we want to stay for a couple of days. Thanks again!

Thanks we will explore the options with easyjet

Renting a car will not be an economical way to go. You will pay a hefty fee to rent in one country and return in another. That isn't even counting fuel and other costs of driving in certain countries like Switzerland. I wonder if Ralph would suggest that his girlfriend, wife, mother, sister or daughter should hitchhike around Europe.

Easyjet is showing $158 per person for the Geneva-Amsterdam flight on Aug. 17 (departing at 7:15pm). I would hop on that immediately. Train fares for this route are likely to be more expensive. And the routes through Paris, for instance, involve transferring between Parisian stations on the metro (Gare de Lyon and Gare du Nord). There are direct buses from the Amsterdam Airport (Schiphol) to Haarlem.