Some understanding of HTML, CSS, and JavaScript would be good, especially if you want to code some logic into the chatbot yourself or customize it to look cool. However, you don't need these skills to start building Botpress chatbots. I think a good way to start learning how to build Botpress chatbots is to watch all the short videos on their YouTube channel, pick the long videos that interest you the most and that you want to learn how to make, and when you watch the tutorials, don't just watch but build along. You learn to build chatbots by building them every day, and when you come across something you don't know, look for information in the documentation and ask here. Practice is key, and when you practice, your brain learns best from mistakes and surprises; I deal with both of those on a daily basis!