I'm trying to open up excel 2013 on my laptop but I get a notification when I open up a new workbook that most features have been disabled because the account is not activated. I don't know where to find the product key neither do I have the money to pay for the Microsoft 365
MS Office 2013 came in two very different installation types -- local and Click-to-Run (CTR). In the first type, you got information with the laptop containing the MS Office product key and you should have used that to activate it. In the second type, you got an email to contact Microsoft, who then sent you the key via email.
We have no way of accessing or retrieving either of these -- so we can not help you with this.
You will need to contact HP Customer Support yourself to see if they can provide any assistance:
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