Question about Dell UltraSharp U3425WE

I have seen or heard in a review video for this monitor that the monitor has to be calibrated manually. However, as I am a complete beginner in this area, I would like to avoid this. What does this mean for me? Is the picture on the monitor still usable or do I still have advantages over a monitor that covers a smaller range of colours? I'm only interested in the general impression of the image, I'm not currently planning to use it for colour grading videos or anything else. Many thanks in advance for your feedback!