how to install office home and student 2019 on a new computer

I purchased Office Home & Student from Best Buy when I purchased my new computer.  How do I install what I purchased

Which instructions did you receive with the purchase? You need to follow those instructions.

Thanks in advance for your help

I got a 25 character key for Office Home and student 2019.  I couldnt load it.  I called microsoft and they helped me through it, but it still wouldnt load, and says I should go back to the retailer, which I did.  THey said it was activated fine and the problem is with Microsoft.

So in reading the answers in this group chat, I found that I was supposed to remove the preinstalled version of Office 365.  I did that today, but Office 2019 still wont load.  What am I doing wrong?

Which error messages are you seeing, if any? Typically, you enter the product key for a perpetual license in the form at https://setup.office.com. You will be asked to associate the product with a Microsoft account. 

If you are trying to reinstall Office, use your account. Note that you may have to activate by telephone. If an error message is shown, locate the phone number for your region in the article at https://support.microsoft.com/en-us/office/-telephone-activation-is-no-longer-supported-for-your-product-error-when-activating-office-9b016cd2-0811-4cb3-b896-5a6a13177713.

We just bought a new computer and a copy of office home and student 2019 and can not get it to load.

we bought office home & student (2019) a few weeks ago we installed it on Microsoft 365 - the problem that we are having is, it's asking for a subscription. Why is it asking since we already paid for it? Help, please. We need it for school.