Some little kid told me that trample damage does not hit the player if the trampling creature dies in combat. Is this true? So if my 10/1 trample creature is blocked by a measly 1/1 goblin token, will the player receive no damage?
No, that's not true. Trample goes through even if the assigned blockers have enough power to block it. Combat damage is all dealt at the same time, so your trampler is still alive when he is trampling. Now if something outside of combat damage kills your trampler first, like first strike or a {lightning bolt} before combat damage, then your creature is dead before it can deal any of its damage.
Cards like {Elemental Appeal}, {Ball Lightning}, and {Hellspark Elemental} would not exist if what that kid told you was true ;)
RESOLVED
You have been told incorrect information.
The only case where this is actually true is if the 1/1 has first strike or double strike and kills your 10/1 before it can attack.
Otherwise all damage is dealt simultaneously.
Well sucks for that kid cuz it lost him the match not me ;) he shot himself inthe foot and got me an extra pack for the draft! Woo'