There are many kinds of sonnets. Shakespeare’s sonnets are not the only option. There are sonnets that stick to the Italian method. There are ones that are only concerned with iambic pentameter. One only contains the word watermelon over and over again for fourteen lines, and it is still technically a sonnet. Gerald Stern has his own kind of “American” sonnet.
But for the purposes of our prompt your sonnet must contain 14 lines. It is up to you if those lines contain rhymes or iambic pentameter. For this prompt your sonnet must also contain a turn, the traditional twist of Shakespearean sonnets, where the last two lines alter the meaning of the rest of the poem.
Now if you want to see a few sample sonnets, I have included links to a number of sonnets below, all follow different guidelines for what it is to be a sonnet, although all contain 14 lines and a turn.
I will put Chaos into Fourteen Lines, by Edna St. Vincent Millay