@Willsoon
You can fly to Amsterdam or Eindhoven and take the train to Maastricht.
Check the train schedule
here.
A: From Schiphol you can take a train to Amsterdam Centraal (~15 min.) and from there, a direct one to Maastricht (2h 26m).
B: From the Eindhoven airport you need to take the bus to the train station and from there, a direct train to Maastricht (1h 11m).
I tried both the above options and I didn't have any problems.
PS: When you arrive in the Netherlands, you should buy a Strippenkaart from a kiosk.
I found out that the Strippenkaart is a cheaper way to travel by bus than buying 2 journey tickets from the driver.