Most travelers arrive through Tivat Airport on the coast or Podgorica Airport near the capital. The smart move is to install your eSIM at home on Wi Fi, days before you fly. Then you walk off the plane, turn on data roaming for the MegaEsim line, and you are online before you reach the taxi rank.
Both airports have good mobile signal, so you can pull up a map, message your driver, or book a ride right away. For a short stay that is mostly arrival logistics, the 1 GB for 7 days plan at $1.53 is enough to get you settled and find your hotel.