Putting a picture INSIDE the e-mail is slightly different.
When writing an e-mail you can either specify it as plain text, or as an enhanced format like HTML. You can control this with your e-mail program
If your e-mail system is setup to only send in plain text you cannot put a picture INSIDE your e-mail.
If you set it up as HTML then you can put a picture inside the e-mail, but if the person who recieves it has THEIR e-mail set up as plain text they will not see it (it will probably come as an attachment)
You can use cut copy and paste from the edit menu.
Normally you COPY the picture into the clipboard then PASTE it into the e-mail.
You can practice cut copy and paste with a program like Microsoft Wordpad that comes free with Windows.