How do I reset my MacBook

Why do you want to reset your mac, what is the problem.

The first thing to do before you decide to reset your mac is to have a copy of the OS you want to put back on your mac

on a bootable US flash drive, do not rely on Apples Recovery Servers.

Which OS do you want to install on your mac. If you have a Mac Min from 2018 then it probably came with either

macOS High Sierra or macOS Mojave preinstalled.

Read this article,

How to create a bootable installer for macOS – Apple Support (UK)

You will be able to download the full installer apps from the links contained within,

only use the Safari browser when clicking on the links.

Once you have downloaded the full installer app you can then create the bootable installer from the instructions

in the linked article.

Now make a full backup of your mac.

Next you boot to the bootable USB installer.

From the Utilities window select Disk Utility and press Continue.

Click View in the menubar and select Show All Devices.

Highlight the Disk (probably called Apple SSD...... or similar)

click Erase.

Give the Disk a name.

Format: APFS

Scheme: GUID Partition Map

Click Erase.

When Done quit Disk Utility.

Select Install OS press Continue.

Without further information on why and what you want to do, and what mac you have

and what OS you want to install it is difficult to give you exact instructions.