Can an email have a background picture and my own fonts?

Yes. In the email builder (a campaign in Email Campaigns, or the welcome email), click an empty part of the page so that no block is selected. The panel on the right shows Email Design:

• Background Picture: a picture behind the whole email. Your headings, text and buttons sit on top of it.
• Email Color: the color behind your blocks. With a background picture it shows in an inbox that has pictures switched off, so pick a color close to the picture.
• Text: Dark text or Light text. Light text is for a dark color or picture.
• Side Margins: Standard or Wide. Wide keeps text in a narrower column. Phones always use Standard.
• Page Color: the color around the email.

Fonts are the same in every email you send. Set them in Email, Config, Fonts: a Heading Font for Heading blocks, a Body Font for text and buttons, a Text Size and a Line Spacing. The fonts are the ones the website builder offers, so an email can match your site. Apple Mail and the iPhone Mail app show them as chosen. Gmail and Outlook cannot load a font, so they show a similar standard one.

A Heading block has a Size from Small to Extra Large, an Icon (a small picture to its left) and Line Under Heading (a line in your button color that starts at the icon). A Divider's Line is Thin or Bold. Button Size, Standard or Large, is in Config, Buttons. Inside a Text block, Heading 1, 2 and 3 in the style menu make a larger bold line in the body font.