Should I learn Typescript?

YES.
TypeScript is strongly typed, errors will be highlighted at build-time, not run-time, auto-docs and Intellisence is super valuable, TS has additional syntactical features that JS doesn't.
Check out this SO post for more info: stackoverflow.com/a/12694578/979052

Yes.
Also, typescript == Javascript. The only thing that typescript adds is the option to strongly type your javascript by defining types.

// This is valid javascript AND typescript:
function myFunc(someParameter) {
  return "hello world!"
}

// This is valid typescript with types:
function myFunc(someParameter:string){
  return "hello world!"
}

Because it is strongly typed, typescript will help you to catch errors in your code at build time, instead of runtime and infact if you use visual studio code. It will highlight errors for you before you even attempt to compile your code.

Its also important to note that typescript does type inferrence. Take the code snippet above for example. Typescript will automatically infer the return type of myFunc, you do not have to explicitly define the return type, unless you want to:

function myFunc(someParameter:string):string {
  return 123 // This will produce an error in typescript because we defined the return type needs to be a string
}

You should learn Typescript - it's in your benefit so long as you continue to write and maintain JavaScript projects.