Okay, try this.......
Hoover your Aristic Text tool over your trapezoid until you get a lower case "ab" enclosed in a small rectangle.
When the "ab" appears, click there, on the insertion point. Corel will automatically create a paragraph text box that conforms to the shape of your trapazoid.
All you need to do is start typing away and Corel will fit/wrap the text inside that container for you.