Can I transfer my photos from my iPhone to my iPad without using my computer

You can use iCloud Photo Library to sync your images to all your devices. You enable this function in Settings > Photos & Camera > turn iCloud Photo Library ON.

If you have a lot of images, it will take a long time.

iCloud Photo Library is probably your best option: iCloud Photo Library - Apple Support

metramama wrote:

Can I transfer my photos from my iPhone to my iPad without using my computer?

How to use AirDrop with your iPhone, iPad, or iPod touch - Apple Support

Depending if you have the system requirements, I use airdrop to transfer pics from my iPhone to ipad and mac.