"but when I make an offer, I get "Sure, that you want to pay more than these goods are worth?" I mean, what the heck does that mean? It doesn't even make sense?!"
It means you have more items/gold in your trade window than the other person has in theirs. You can use the balance symbol by each portrait to remove gold from your side or add gold to theirs to even the values off (as much as possible).
"So, I choose 'accept', and absolutely nothing happens. Is that normal??"
The trade should go through; your trade items removed and the other NPC's items added to your inventory.
"This other character tells me to round up some herbs, but I can't."
ALCHEMY SPOILER THREADOr are you referring to George? After you do Lanilor a favour, you can ask his permission to gather some Drudanae herbs from his garden.
It does get better.
Early Starting TipsEarly Starter Tips (NON-Spoiler Version)Starter Tips? (Spoilers)