Hello there, JacklynG23.
It sounds like you are trying to hide photos that you do not want to show on your iPhone 6s Plus. The following link to the iPhone Online User Guide provides the information on how to do just that:
Organize photos and videos - iPhone User Guide
Hide photos or videos you want to keep but not show. While viewing thumbnails, tap Select, then select the photos or videos you want to hide. Tap
, then tap Hide. The photos or videos are moved to the Hidden album.
Note: Photos or videos are hidden from Moments, Collections, and Years, but are still visible in Albums.
Thanks for reaching out to Apple Support Communities.
Happy Holidays!