Sidney uses an ABAB rhyme scheme to establish a pleasant, consistent rhythm in this sonnet, ending on a rhyming couplet.
In the first quatrain (first four lines) Sidney uses repetition to place emphasis on certain words: loving/love, she, pleasure, read/reading, pity.
Sidney uses a metaphor, a comparison not using the words like or as, to liken his writing to painting. He also employs a metaphor as he compares himself writing the poem to a pregnant woman in the throes of labor pains.
The poet also uses personification. Personification is assigning human attributes to abstract or inanimate objects. In this sonnet, the poet's process of "Invention," or the work of getting words of writing on a page, is described as a child, escaping the blows of another personification, "step-dame Study."
Through the use of literary devices, Sidney shows, in this opening sonnet, the struggle he is having finding the right words to express his love in a persuasive way.