What is a Sonnet?
There are many different forms of sonnets and none of them are difficult to write if you follow the basic rules:
It must be lyrical -- rhyme and meter should be regular and unforced, so that if you wanted to, you could sing it (that's what sonnet means, "little song")
There should be two parts to a sonnet -- an introduction to a problem or situation set-up and a resolution or concluding summary
A sonnet is not a narrative. It is a lyric poem, often used to explore love or philosophy, but could be any theme you choose.