I think this version is better:
People say that we should first meet a person before judging their virtues and flaws. But, it is difficult to put it into practice.
Usually, we first imagine how a person is and when we interact with them we make a first impression about them. Only through everyday interaction is that we can change our wrong idea about them.
For this reason, I believe we should care about the first impressions that people will have about us. If we give a wrong impression of us, it will be difficult to change the misconceived idea that people have about us.