You can have Internet almost immediately.
MobiFone currently offers an eSIM designed for international visitors.
The operator offers an eSIM that provides 10 GB for the first 24 hours after activation, subject to meeting the conditions and identification procedure.
For e-visa holders, registration can even be initiated before arrival.
The procedure notably uses the passport and an identity verification.
This can be an excellent temporary arrival connection.
But if you are settling for several years, then take your time to choose your permanent plan.