I am still a beginner and I don't have that much experience, but I will tell you what I think.
1- Do real-time projects: think what can you do and see chatbots from websites, then try to apply it with yourself.
2- Help others, for me to get the maximum experience at any field, you have to help or demonstrate what you learned to others.
3- Try to get work, you can make simple projects and put it in your portfolio, then upload it at freelance sites. You may think that no person will ask for this simple task, but actually there are some will ask for it, because it is simple for you not for them and it can be simple but they are busy to do it. You can also search for local small companies that at the beginning of there project, they might need a simple chatbot.
That is my opinion, what do you think?
I would like if there are more people sharing there experience too.
Good luck!