We want to visit a couple of cities beside Amsterdam like Haarlen Delft and Enkhuiizen Would getting a car instead of a train
work and is the cost a lot more We are going in April
Are you staying in central Amsterdam? If so, it is no place for a car, and trains in the Netherlands are very frequent and super convenient. There are a variety of passes, or get a Tripkey and pay as you go. You need your ticket, pass, or Tripkey (or OV Chipkaart) to exit stations in the Netherlands. If you buy individual paper tickets, you're paying a small surcharge on each ticket to cover the cost of the embedded chip.
If you get a car, you'll be paying through the nose for parking in cities.
Be sensible and take the train. This train planner shows you how frequent and fast they are.
No point in a car for those locations.