Realistic Expectations
Don't expect your first song, or your first hundred, to be hits. It took years or decades for most successful songwriters to start writing cuttable songs. More importantly, it usually takes writing lots of bad, mediocre, and good songs to work up to writing great ones. Give yourself time to grow artistically without the pressure of coming up with a hit song right away. Remember, writing a bad song is more fun than not writing at all. Even hit writers come up with a stinker every now and then. As you learn and develop, your percentages will improve.
There's no preset number of songs you must write before you get a winner. Some songwriters write thousands of songs and never get a break. On the other hand, Laura Nyro and Holly Tashian each had cuts (commercial recordings) with their very first songs. For most songwriters, it takes a few dozen songs to get to the first good one and several times more to start writing cuttable songs. Just remember, if you go see a publisher with three pretty good songs, you probably won't be invited back. Give yourself time to learn what you're doing. After your hundredth song, you will probably look back at that first masterpiece and laugh, cringe, or both.
Many songwriters start with simple songs for and about their children, families, and friends. This has the advantages of being a topic you know well and a built-in market — who wouldn't be tickled to have a song written for them? As with all writing, start with what you know, keep it real, and worry about the fine points later. Above all, have fun and enjoy the opportunity to express yourself in music.
Writing a lot of songs can help you become a good songwriter but it's also important to give each song a good effort instead of hurriedly writing a million songs. It's the habits you develop and lessons you learn in writing many songs, not the sheer number of songs you write, that makes the difference.

