New iPhone 6s freezes

I just got my new iPhone 6s yesterday and noticed that it freezes or shuts off apps infrequently. For example, while I was typing a text, it stopped so I had to wait for a few seconds until the cursor re-appeared to continue my typing. Also, while I was trying to email photos, the email closed out itself for a few times. I had these issues more frequently with my 5s and I thought it was time to upgrade. And I really hate to see the same issues with this brand new phone. Any thoughts, solutions or suggestions?