How/where do I report dividend income from a trust? I have only a "grantor statement," no other tax form?

You can report this as if you received a 1099-DIV.

Enter all income from the grantor statement under the relevant topic in TurboTax. Dividends are entered under Federal taxes >> Interest and Dividends Income. 

The easiest way to find any section of TurboTax is to open your return and use the Search box at the top right side of the TurboTax header. Click on the magnifying glass, type in the topic you need, hit Enter, and click the "jump to" link to go directly to beginning of that topic.

Or in TurboTax Online, go to the left column and click on Tax Tools >> Tools >> Topic Search. Type in your topic, then click the topic in the list to go directly to the start of that section.