I sent a spy probe to a planet and it returned info w/no defense. How then, can I lose my entire fleet in the first round of the attack.
Is it possible that though he shows no defense, he still has one or that he has an alliance that is protecting him w/o being formally a part of it?

You either did not send enough espionage ships to get a full report, or your level is not high enough. Never attack unless you see the bars for fleet/defenses/buildings - if you only get the resources and energy you don't have the full report!

OR, the player built defenses and pulled a ninja (of sorts) on your fleet.
This is something that every newcomer comes up against...

Ok. Well, I guess I got Ninja'd. My entire fleet of 250 or more was destroyed. I will take your words and advice with great consideration
from here on.

Thank you for your help.

Vahl