"Happy Chanukah," is a fine greeting and one commonly used among Jewish communities.

I have a necklace with yhvh in Hebrew. I am not Jewish and I love God. Would I offend if I wore it?

Wearing a Star of David or any traditionally Jewish symbol when someone isn’t Jewish would be cultural appropriation and is best avoided.

What's a good resource to start learning about Reform Judaism?

I’ve been so overwhelmed and distracted that it’s been difficult to focus on any one thing let alone gratitude. How am I supposed to know what I'm thankful for when I don't even know what day it is?

Jews of all political affiliations are generally offended by uses of Holocaust and/or Jewish imagery for things not directly related to Judaism or the Holocaust.