If I were you I'd want to really good with plain Python (or Node) before learning a framework, but that's because I'm the kind of person who wants to know how everything works. Once you've written a few CRUD apps you'll wish there was a tool to do some of the common stuff for you, and Django will be waiting for you.
But, if you're not that kind of person it's perfectly OK to jump straight into Django. You'll certainly get further more quickly, even if you won't be able to explain exactly what your code is doing.
I don't think it's that important what technology you decide to learn first, largely because learning new languages / tech stacks gets easier as your frame of reference grows.
What I think is important is sticking to one thing until you have a good grasp of it.
But, if you're not that kind of person it's perfectly OK to jump straight into Django. You'll certainly get further more quickly, even if you won't be able to explain exactly what your code is doing.