I like this guy and have started dating him but he has a child from a previous relationship and I always told myself I would never date someone with a child. But I really enjoy his company. Do I have to stop dating him?

Why did you tell yourself that you wouldn’t never date someone with kids? Some people call it baggage, I call it added bonuses and more to love. A man with children can be more mellow that a man without. If you have dated many younger men, this one having a child might be more responsible. If you really enjoy the company of this guy then why not continue dating him and spending him with him and his child and see what it brings to your life. You will only know if you give it a try and can’t base your decision on things you once upon a time told yourself, and probably based on no or little experience or information.
This might also hold some challenges for you. Having a child around means structure and also that their needs come first. That is something you need to accept and understand if you are continue to date him. It’s not always easy with children around but can be very rewarding. The test will be how strong your connection and relationships is to be able to survive any challenges that arise due to the dynamics.
Enjoy being able to tap into your inner child, to not be a parent but look after someone who needs it. But be sure to discuss any issues that arise and be careful that if you do stay here you know that you will have to look out for someone ahead of you. You are not just dating one person, you are getting involved with someone who doesn’t have a say and there will be a duty of care that you should be mindful of.