How can I add Microsoft Word and Excel on my new iPad?

Expanding upon information already provided by Servant of Cats...

There are individual Microsoft Apps for Word, Excel, PowerPoint, Outlook etc. intended for iPad. iPad models with a screen size of less than 10.1” can access a restricted set of App features, including creation and editing of documents, for free. 

For iPad devices with a screen larger than 10.1”, the MS App’s require an active Microsoft 365 Subscription. If you don’t have an active O365 subscription, functionality is limited to opening and reviewing existing documents.

All the Microsoft Apps for iPad can be found in the Apple App Store.

Microsoft Word, Excel, PowerPoint, Outlook and others are all available from the Apple App Store. All now require iOS/iPadOS17 or later.

• Word

https://apps.apple.com/gb/app/microsoft-word/id586447913

• Excel

https://apps.apple.com/gb/app/microsoft-excel/id586683407

• PowerPoint

https://apps.apple.com/gb/app/microsoft-powerpoint/id586449534

• Outlook

https://apps.apple.com/gb/app/microsoft-outlook/id951937596

• Teams

https://apps.apple.com/gb/app/microsoft-teams/id1113153706

• OneDrive

https://apps.apple.com/gb/app/microsoft-onedrive/id477537958

• Authenticator

https://apps.apple.com/gb/app/microsoft-authenticator/id983156458

• OneNote

https://apps.apple.com/gb/app/microsoft-onenote/id410395246

In summary, MS Productivity Apps for iPad (such as Word, Excel, PowerPoint) offer limited functionality without an Office 365 Subscription - but only for devices with a screen size of 10.1” or less. Devices with larger screens only permit you to view (but not create or edit) an existing document. Full App functionality requires an active Office 365 Subscription.

Microsoft has iPad versions of Word, Excel, and PowerPoint. I don’t know how they compare to the Windows & Mac versions, but you can download them from the App Store.

To edit any documents with them, I believe you will need to have an active Microsoft 365 subscription. Microsoft offers free accounts to people whose devices have sizes smaller than 10.1 inches, but that would not apply here.

Microsoft – Compare all 365 Products

Here's Microsoft's page where they talk about what you get with a Microsoft 365 Personal or Family subscription. I am guessing that you can pay Microsoft directly or through in-app purchases, but check with Microsoft if you're not sure.