Hi @dazzray1,
Welcome to the Community!
You've not mentioned what type of file you're adding from your phone. The trick to attaching files (pictures, articles, etc.) is to go to the file FIRST. Most will include an icon (looks like a square with an up-arrow) that you can click, in order to share/send it to various places. You should see the option there to send it in an email. Once in the email app, you can write your message.