i just went from HD to voobly, and i noticed that there's a significant delay in the reaction time from units after a command. i.e.: when i click a villager and right click a farm, it takes 1-2 seconds for the villager to start farming. this goes for all units and buildings and all commands.
How can i fix this?

Hello,
Your might have a high ping while playing, that why your game is lagging.
Just try to reduce your lag by closing your browser while playing and some apps that might make some updates frequently.
Since you're new to voobly you might also be fp (fast proxy) that will cause alot of lag during play so if you joined any room and you noticed that you have a yellow triangle then you must contact a Technical Support to assist you.

Another important remark is to use the v1.5 Beta R7 Patch instead of the 1.4RC. You find the Settings option next to the launch button in the Game room. From there you can change the user patch. Cheers.