How to add hand movements when singing lyric songs on the stage? Or the skill of adjusting the atmosphere.

Lyric songs should not have too much hand movements. You can wave your hand and do some extended and cyclic actions with music and lyrics. Don't stand still in one place, you can walk on both sides of the stage with vivid expressions. It's like telling a story when you are emotional. The key is that your expression and singing skills can't impress people.