A clear narrative sequence means that your poem or story needs to have a beginning, middle, and end. You'll need to tell what things happen first, next, and last. For your first time writing a narrative story/poem, you'd probably want to start by making a list of the things that happen so that you can be sure to include them and make sure that they are in order. Once you start writing the story/poem, you can refer to the list to make sure that you have everything.
Sensory language means language that expresses the five senses of sight, taste, sound, touch, and smell. For example you could describe the way the tiny bumps on a strawberry feel on your fingers or the sweet juiciness of its flavor. A blanket is soft and fluffy, while a brick is heavy and course. These descriptions add to the reader's ability to "see" or "feel" or "hear" etceteras what you are describing.
Hope This Helps.