Question about POE procedure

So, I'm all packed, and within the next week or so, as soon as my student visa approval arrives, I'll be heading up north. I've got my lists and my B4.

Here's my question though. My father and sister are coming with me for about a week so they can help me unpack and meet my housemates. We're using my brother's truck to move, that's what we'll be driving across the border and what my sister and father will be driving home, minus me and all my stuff. I know when I cross the border I'll need to do my POE and visa interview, but what should my father and sister say? Should they just tell the border agent that they're coming with me for a temporary visit, or is there something special they'll need to declare?

Just covering all my bases. While we're at it, do I need to declare the boxes of tea I'm bringing with me? It doesn't really count as a live plant or a fresh vegetable, but I'm thinking I will just to be on the safe side, and it's all listed in my giant list o'doom anyway. Thanks in advance!