Depends on the situation ! I get nervous when I have to go to the wound clinic every week and see what they say about my leg healing. Good news? I relax. Bad news ? I get nervous. Otherwise, it's perfectly normal to be nervous over certain things.
Absolutely. I am really nervous when traveling near semi trucks now due that accident I mentioned under a different question. Whether it's from a bad experience or an unsure expectation, it's quite normal to feel nervous.
Yes, I get nervous in different situations.
Although this'll be very similar to other answers, it definitely is. You may be referring to random situations like talking in front of others for example, and different situations make different people nervous. If you are constantly nervous, don't instantly assume anything. It could, yes, be anxiety, but I tend to be nervous about many things and that could just mean you are sensitive, and wary about things you do. Sometimes that can be a good thing :D