For Your First Song, I recommend starting with a song that you're passionate about or that makes you feel something. For instance, if you're newly in love, you're in a good place to write a love song. If you've recently had your heart broken, it might be a good emotion to discuss first. Start with an idea that is meaningful to you.
You can write a song about just about anything. However, be sure to choose a topic that interests you. It'll be much easier to write and you'll end up with a more powerful song if you start with an idea that means something to you. When it comes to writing songs, start small and move forward.
Some people prefer to start writing with the letters done first, which is totally fine. If you start the process more naturally by playing an instrument, many artists have found the spark in their song starting with a simple hook or melody. Create a stanza or a chorus and see where it takes you. You'll usually find them between the last stanza and the chorus of a song before the replay, as they help bring the song to the climax.
Some songs will never grow beyond a certain stage and that's the way it is and that's okay, there will be other songs. Some songs need a little discipline to finish them, others will die halfway through, and anything you write after a certain point will never sound quite right. You can record it on your phone as a clip in mp3 format, but be sure to record it in case you forget the sound of the song you wrote (it's a more common problem than you think) and write down the lyrics and chords in a songbook or diary. If you're having trouble joining parts of your song together, try writing transitional sections, such as presets or instrumental pauses.
As a musician, I have often noticed that the strangest events in my life often become the subject of the songs that my bandmates and I have brought to the writing table. So you decided to try your luck writing songs, right? Are you the emotional teenager trying to make sense of what you're feeling or the lover in love who scribbles ballads of eternal love? Maybe you're a tired twentysomething who has found a cause you want to fight for, anyway, you've decided to embark on an artistic journey of creation.