I think, it is important to know where the language and paradigms are coming from and what you deliver to your clients, so I discourage learning TypeScript first. Knowing JS can help you with a lot of TypeScript problems and enables you to include JS files into TS without a problem.
However, I do not want to suggest that you become a master of JS first. It is enough if you understand basic principles about JS, so you can read, understand and solve problems in vanilla JS. If you still feel the urge to learn TypeScript as fast as possible, you can then switch over and immerse yourself.