Do i need to buy Minecraft 2 times for 2 people to play on a pc & laptop?

Your won'be able to similtaneously play it on the same account. Instead just make two accounts (one with Premium status and one without the full game). You can install it on both computers

Silly, right?

Thank you.
but if they want to play simultaneously, I will need to purchase it 2x? Is this correct?

Yeap