How to match chords in piano improvisation accompaniment?

My piano teacher taught me that the first song I learned to improvise was Farewell. This is a farewell symbol. The first sentence is 535 1, so you can use 135 1. The last 1 here is a treble 1, so that the left hand can repeat it twice. The second sentence 6 15 is 6 1, followed by the left hand 15. Like this, if the first sound is 5 or 3 or 1, use 135, and if the first reason is 6 or 4 or 2, use 246. If you are not clear, add me QQ472020563.