My girlfriend told me that she would travel with me in the future, but I was very dull. When she agreed, she became angry. Why, should I?

Even if it's not your girlfriend, others will feel bad about your warm invitation and your dull reaction.

Take the initiative to find a travel guide, design a good route, calculate a good budget, and then share your plan with your girlfriend. She thinks that if you take what she says seriously, you won't be angry with you.