pages and numbers

Open the Mac App Store & hold down the option key while clicking the Purchases tab on your High Sierra Mac. If you see Pages, Numbers, and Keynote with Update/Install buttons, it may offer to download a previous version of these applications compatible with High Sierra.

In Mojave and later releases of macOS, one must enter ⌘+0 (zero) to get to the previous purchases panel in the Mac App Store. This changed from the option+Purchases tab in High Sierra and earlier.

Click on the "Store" menu & sign out & then sign in again. Even though it said I was signed in with the correct account the I would get a message that I needed to sign in to view my purchases.

I don't know if your App Store purchases list is long like mine is, but I find it very difficult to find specific apps in the list. Apps are listed in reverse order of purchase date but dates seem to change & there doesn't seem to be any rhyme nor reason for the order in the list. I originally purchased Pages 5 & Numbers 3 when they first came out although that was considered an update/upgrade of my iWork '09 apps. But, for some reason, they appear in my purchases list with a date of February 2018 in the Mac App Store on one of my High Sierra Macs.

If you simply do not have Pages and Numbers installed, and/or the Mac App Store has no solution for you, then sign in to iCloud and use Pages and Numbers there.