1.”First of all, don’t panic,”Turn off the laptop and disconnect it from its power source & battery immediately.

To disconnect the laptop from a power source & battery, simply remove  the charger cable from the laptop.
If the laptop is left on, even for a few extra moments, you could cause a short circuit, leaving the components inside with permanent damage. The quicker you can turn off the machine, the better chance you have of saving the laptop.

2. Turn It Upside Down and Let It Drain

Take a dry cloth and wipe up any excess liquid from the surface of the laptop — especially near the keyboard.

Never use a hair dryer to speed up your laptop’s drying process.

3. Turn the laptop upside-down and remove the battery if possible.

If you can easily remove the battery, that should be your next step.
This step is not possible on some laptops, including MacBooks without first unscrewing the bottom of the laptop from the rest of the housing.

4. Unplug all external hardware.

• USB devices (wireless adapters, chargers, etc.)
• Mouse
• The laptop charger