There's no reason to import modules you don't use; and every reason not to: doing so needlessly increases the load.
Finally, importing a module twice is pointless and confusing.
import A from 'a'; // Noncompliant, A isn't used
import { B1 } from 'b';
console.log("My first JavaScript...");
import { B1 } from 'b'; // Noncompliant, already imported
console.log(B1);
import { B1 } from 'b';
console.log("My first JavaScript...");
console.log(B1);