My screen do not work smooth

Well you can apply these fixes-
Lower refresh rate — Go to Settings → Display → set to 60Hz if on higher

Clear cache — Settings → Storage → Clear Cache

Disable animations — Developer Options → set all animation scales to 0.5x

Uninstall heavy apps — Remove apps running in background

Free up RAM — Close all recent apps regularly

Factory reset — Last resort: Settings → Backup & Reset → Factory Reset

Update software — Settings → Software Update → install latest version

Most common fix is clearing cache + disabling animations — try those first before anything else.