Share all my notes to another iPhone

If the other phone has the same Apple ID (and it shouldn’t, unless they are used by the same person) just turn on iCloud sync for Notes: Settings[your name]/iCloud - Notes=ON.

If you are sharing with someone else just share the folder or folders the notes are in.

You can share individual notes and note folders. See this for more details→Share your notes on your iPhone, iPad, or iPod touch - Apple Support

Do you mean share as in your keep them and they have access to them, or do you wish to copy them and put them on another device, or are you referring to getting them on to a new phone?