Hi there Chance2021,
Thanks for reaching out to Apple Support Communities. It sounds like you’ve set up a new iPad, using a backup from your previous iPad but Photos are not all showing up. We know how important it is to have access to those memories. We’ll be happy to help.
To start, follow this guide: If you're missing photos or videos in the Photos app. Keep in mind that after enabling Photos in iCloud on the iPad, it may take some time for that process to complete and show your photos. You’ll want to connect to Wi-Fi if possible.
For more information on how this works, check out the Photos section of this page too: About missing information after you restore your iPhone, iPad, or iPod touch with iCloud Backup. We hope this helps.
Best regards.