Put down an inherited timing section on the sliderend and tune down the volume to 5%.
You could also silence it completely through using a hitnormal with no sound but that's generally discouraged.
For the next note you should put down another inherited timing section and readjust the volume.
I recommend you asking in the #modhelp channel ingame for such simple questions as you'll get help there a lot faster than here and most mappers in there will be able to answer you these correctly.