I wrote a song with lyrics, and I also played a notation on the guitar and drew it, but how can I match the chords next?

You can use chords in C to match songs. Generally, songs starting with 1 are major, songs starting with 6 are minor, and songs starting with 3, 5 and 2 are determined according to the nature of the melody itself. First, find out which chord the notes of each bar are biased towards and match that chord, such as a four-beat song. At the beginning (the first bar), the note 1 3 5 accounts for three of the four beats. By analogy, there is another problem to think about, that is, the direction of chords, such as C-F-G7-C, C-AM-F-G7-C, C-G-F-G7-C and so on. "Four beats four" beats, one bar can be matched with two chords, and the above is the matching method of major chords. The arrangement of minor is the same as that of major. For example, 6 1 3 with Am chord and 2 4 6 with Dm chord. Chord direction in minor such as AM-EM-DM-AM, AM-DM-EM-AM, and chord arrangement in major such as AM-G-F-EM-AM, AM-DM-G7-C-AM can also be added.