First, acquire the basics on the guitar, keyboard or piano as you will be using any of the three instruments when creating a melody for your lyrics. Be aware of the fact that almost all professional lyricist use at least one or all of these tools while writing. If you wish to become a lyric writer, you need to write all the time in order to maintain a decent flow. Note down good ideas on a notepad and cocktail napkins. It is vital to keep a notes with you so you can write down any great and inspirational thoughts and ideas.
Join a writing course
It is better for your writing if you take a course on learning how to write for music, singers and bands. This will offer you some basics of writing lyrics that can definitely help you in the long run. You can learn the fundamentals if you enrol in a community college. These colleges will also assist you in guiding whether you want to pursue this career option or not. Taking a few courses at a community college is relatively inexpensive but can give you a head start to writing lyrics.
Poetry and singing
You can also write poetry to improve your lyric writing. Make sure you know that poetry is not similar to lyrics and has feelings and emotions in it.
Furthermore, by writing poetry you will be able to convert it into lyrics after some time. You should sing your lyrics loud as well. This will help you determine if the lyrics sound good, despite having limited knowledge about music. You can visualise being a listener so that you determine the quality of your lyrics. It might be a good idea to buy a book on rhyming words that can help with your lyric writing.