Welcome to the forum.
I don't have EZD, but I assume it works like most other soft synths;
Insert synth
Set output of synth to a valid sound device
Put MIDI info (notes) in a MIDI track
Set output of MIDI track to soft synth.
What is the output of the MIDI track you're dragging the MIDI patterns into set to?
What is the output set to of the synth audio track?
What's you're sound card or audio interface?
What's you're operating system?