I was wondering, if I drop below 0 Reputation Points, does that mean I get a warning, or what does it mean?

I've been downvoted once in my thread, but it actually shows 3 downvotes on my reputation, which doesn't make sense.

I have a lot of honest things to say. My reputation should be great, not bad.

Honesty = Good Reputation

Bad Reputation = Lies, Deceit, and Dishonesty.

Don't stress over your reputation. It is more a gauge for others to see if you are a helpful community member or not. No one is targeting you because of being new. In truth, everyone here has started as a beginner and some have thousands of rep points due to helping others solve their problems. You aren't giving yourself enough credit and need to decide what discipline you like and start learning the ins and outs of it. Just go slow and learn.