This is about as basic a question as it gets. How do I pick stuff up?

Example, right at the start, Herbs and Mushrooms. The manual says to use the mouse pointer, then click and drag. All this does is move my character across the screen.

What am I missing here?

Most plants can not be picked up. If you know the Alchemy skill you can drag and drop an empty potion bottle onto certain plants to make potions (dropping a stack will use one bottle and leave the rest where they were).

Using the mouse to drag and drop will work on potted plants, some furniture, barrels and chests, vegetables, pots and pans, books and letters, etc.

Ah I see. Thank you.