What traits/characteristics do you have to acquire in order to be a psychologist?

In my experience you will need to have a great deal of patience, understanding, and great respectable customer service skills. Psychology is the knowledge of another through the mind, so quickly being able to understand and relate is very vital as well. Good luck!

One of the cliches -- which doesn't mean it isn't true, just that you hear it a lot -- is that a psychologist gets into their profession because they think they or someone close to them needs counseling. Whether that's true or not, it is true that a psychologist -- or a psychiatrist -- is most likely to be successful if the "human condition" is a focus of interest. IOW, you probably need to care about what makes people tick. Generally, IMO, I'd say these are characteristics that are already in you. Either they are active or simply dormant and need to be "activated" by some experience. In my own experience, I was always interested in what motivated people to do what they do. I'd also say that if you do have these characteristics to any significant degree -- that is, relative to "average" -- you're probably already studying "psychology" yourself, whether you're aware of that or not. The interest in human motivation, and especially how to motivate them to be better or more successful or happier individuals and contribute to society itself, is an essential aspect of societal success. Folks who are interested in this tend to be more successful, on average, than those who aren't for a very simple reason. Human achievement tends more and more to be based on large efforts. These effort usually require the cooperation of many individuals. Understanding how these people will affect each others' performance is an extremely valuable trait.

If "human behaviour" makes you read more about it and keeps you involved. It might be something that interests you.

It's good to take a related course from Coursera or any other professional website, and analyse if it interests you. If yes, go for it.