If you have a list of ideas, go for the easiest one first. Don't worry if it seems too easy, or if it's based on a cheap joke, or if people might mock it for being too simple. It's just your first song, after all. It's the warmup lap. You're going to write plenty more.
In the middle of working on a song, if you're trying to get one piece of the song together, go with the quickest and easiest solution. If this spot turns out to be the weak link in the song, you can try a different approach later. But often in songwriting the simplest answer turns out to be the best one.