How can I use two iPads simultaneously?

judith92 wrote:

I just purchased a new IPad. Can I still use my old one?

Yes.

And migrating your contents from old to new — if you choose to do that — will not effect the contents of the old iPad.

(You might be asked if you want to migrate your cellular plan from old to new, though. Whether you have that plan active and whether you then decide to migrate that is your choice.)

If you have various iCloud features enabled, such as iCloud Photos, then your photo library (or whatever other iCloud service) can be synchronized across both iPads, and photo additions, photo deletions, and changes on one iPad are reflected on the other iPad, too. Or for whatever other iCloud service or feature is involved.