It's been awhile since I've up a Win 10 machine straight out of the box.
It should all be preinstalled and I don't think you need to set up a Microsoft Acct. The Microsoft acct just lets you buy stuff from the Microsoft store and have it backup on the Microsoft cloud. Very similar to an Apple account. As with Apple, they will be very persistent in trying to get you so set up an account.
Why set up a new PC with a local account instead of linking it to a personal Microsoft account?
There’s no right or wrong answer. Three reasons you might prefer to use a local account: some people feel that a local account is more secure; a local account allows you to bypass the confusion between Microsoft’s personal accounts and “work or school” accounts; or maybe you just don’t like Microsoft. It ought to be your decision to make.
What is Microsoft doing to hide that option?
Microsoft has repeatedly changed the wording and location of the option to create a local account during setup. Most recently, it has either removed it entirely from the setup screens, or it has disguised it with the words “Domain join instead” – a deliberately deceptive use of a dark pattern to confuse and misdirect you.
How to set up a new PC without a Microsoft account
Do not connect a new computer to the network during setup! Don’t plug in the network cable. Do not connect to wi-fi when prompted. You’ll get an inscrutable error message; then you’ll be able to set up a local account.
After you’re at a desktop, connect to the network or wi-fi. Plan to restart a couple of times to take care of last-minute updates and device setup.
https://www.brucebnews.com/2019/10/how-to-set-up-a-new-windows-10-pc-without-a-microsoft-account/
Here's another excerpt:
Thankfully, there is one hidden way around this process on Windows 10 Home: You can disconnect your computer from the network.
If you have a computer with an Ethernet cable, unplug it. If you’re connected to Wi-Fi, disconnect.
After you do, try creating a Microsoft account and you’ll see a “Something went wrong” error message. You can then click “Skip” to skip the Microsoft account creation process.
https://www.howtogeek.com/442609/confirmed-windows-10-setup-now-prevents-local-account-creation/
Basically go ahead and start to set it up but don't let it connect to the internet and it will eventually allow you to bypass creating a Microsoft acct, You should be able to link it to a Microsoft account if you decide to sign up for one later.
