One of the most common formats for songs is Verse 1, Chorus, Verse 2, Chorus, Bridge, Chorus.
Most verses follow a simple ABAB or ABCB rhyme format - that is, in ABAB, the first and third lines rhyme and the second and fourth lines rhyme, and in ABCB, the second and fourth lines rhyme but the first and third do not.
With choruses, also called refrains, a hook is usually included at both the beginning and the end. Choruses are also sang in a different range than the rest of the verses, to provide variety.
A bridge is played in a different chord, and the lyrics may say something previously unexplored, or deeper in meaning than the verses.
Of course, this is not the only format for songs. Some songs have a more complex structure, such as Intro, Verse 1, Pre-Chorus, Chorus, Verse 2, Pre-Chorus, Chorus, Bridge, Chorus x2, Outro. Some songs do not even have a chorus, or a rhyme scheme. Some songs don't need it.
Simpler formulas are usually seen in shorter pop songs. This doesn't mean the song is bad! Adding your own embellishments to common formulas, or creating your own formula, is how your song becomes your own. Experiment with what you like and choose what makes the music and your words flow the best.