How To Play A Custom Sound When You Right Click A Block?

First, import your custom sound. You need to use an OGG file, with a single mono track. (You can use an app like Audacity if you need to alter it.) 

Make your custom block element. Then go to the 'triggers' section. On the 'block right clicked' trigger, you want to make a new procedure. In that procedure, use the 'play sound' function to play the custom sound you imported earlier.

I don't know if you still need the help as it was basically 3 months ago, but here is an in depth explanation. 

So you have the "ogg" sound file thingimabob, then what you need to do is go to the procedures tab. You can find that by going in the workspace tab, under my elements, then double click the skull. Next, at the bottom, click the triggers tab and then find the "when right-clicked" procedure, then, click the green + symbol and click 'create procedure' (the green button). When youre there, click the grayish box inside of the big green box in the centre of your screen, and where it says filter, type in "player right clicks with item" and when you select it press the "use selected" inside of the gray box. Then, on the left side of your screen, double click on world procedures and press actions. The 4th option down should say "play sound ......" press and hold that option and put it right under the green box, and they should just snap together. After, double click on the "no entry selected" and select what sound you want to play when right clicking the item. Don't forget to save, and after that you're done! (I hope I help someone when they search up a fix on google and find this page)