You can make entire games without touching C++ and do it in Blueprint.
To say that you can make ambitious projects without C++, I would have to say no. You will require C++ at some point.
If you have no background with any programming language (HTTP, Java, C#, etc), you’ll need to learn some basics first to get the most basic out of a game if you’re going to use Blueprint.
You could see Blueprint as a shortcut to learning the basics of programming, but I would recommend to learn C++ along the way.