Open a web browser on your MacBook
Go to minecraft.net
Click Get Minecraft
Choose Mac
Select Minecraft: Java & Bedrock Edition for PC if available
Sign in with a Microsoft account
Complete the purchase if required
Download the Minecraft installer for Mac
Open the downloaded .dmg file
Drag Minecraft to the Applications folder
Open Minecraft from Applications
Sign in with your Microsoft account
Install any required updates
Click Play to start the game