Is there a way to send a photo from my iPhone to someone's email (rather than sending a text)?

It could be that you have not yet set up an email account on your iPhone. To do so, look for the "Mail" app icon somewhere on your iPhone's home screen (it looks like a white envelope on a blue background), then launch the app and fill in all the necessary fields to access you email account. Once you do that, you should be able to use email on the iPhone. You can send someone an email with a photo in it several ways, the easiest being to (as described above) "share" a selected photo, then choose email" as the option; its also possible to just create an email to the person on the iPhone, then "attach" the photo to the email.

Open the photos app. Select the photo. Tap the share button. Select mail as the option. Enter the email address.