I found a script on the internet for installing zynaddsubfx presets but when I tried to use it on the command line I wasn't able to run it. Here is where I get stuck:

emerge -s zynaddsubfx.

This is what it says:

No command 'emerge' found, did you mean: command 'vmerge' from package 'util-vserver' (universe)

Command 'merge' from package 'rcs' (universe)

Command 'fmerge' from package 'fhist'(universe)

Command 'smerge' from package 'tstools' (universe)

Command 'emerge' not found.

Can anyone tell me how to use emerge?