How do I resize photos on my iPad please

What exactly do you mean by "make them smaller"?

1. Smaller as in crop the photo to take section of it, and discard the rest of the image?
2. Smaller as in reduce the physical dimensions of the photo?
3. Smaller as in reducing the file size of the photo?

For the first one, you can use the edit feature in the Photos app to crop a photo.

click here ➜ Edit photos and videos on iPad - Apple Support

For the other 2, you would need a 3rd party app that can either edit the image to reduce its physical dimensions or compress it to reduce its file size.