Help creating a Gulp build?

Question

gulp.js

I would be grateful for the help, since I myself am still a beginner in this matter.
There are the following plugins: browser-sync, gulp-sass, gulp-autoprefixer.
And the following file structure.

• dist
  
• src
  
  • css
    
  • fonts
    
  • img
    
  • js
    
  • sass
    
    • blocks
      
    • style.sass
      
    
    
  • index.html
    
  
  

You need to configure gulpfile.js so that when the "gulp" task is called, browser-sync is launched and monitors changes in index.html, in all js files and in all sass files, compiling the latter into a css file, automatically placing vendor prefixes and displaying changes in real time.
And when you run "gulp dist", all folders and files (except for the sass folder and its contents) are transferred to the dist folder.
Here is my gulpfile.js, tell me where and what am I doing wrong?

let gulp         = require('gulp'),
    browserSync  = require('browser-sync').create(),
    sass         = require('gulp-sass'),
    autoprefixer = require('gulp-autoprefixer')

gulp.task('sass', function(done) {
    gulp.src("src/sass/**/*.sass || scss")
    .pipe(sass())
    .pipe(gulp.dest("scr/css"))
    .pipe(browserSync.stream());
    done();
});

gulp.task('serve', function(done) {

    browserSync.init({
        server: "src/"
    });

    gulp.watch("scr/sass/**/*.sass || scss", gulp.series('sass'));
    gulp.watch("scr/*.html").on('change', () => {
      browserSync.reload();
      done();
  });
    done();
});

gulp.task('dist', function(done) {
    gulp.src('src/**/*.html, .css, .js')
    .pipe(gulp.dest('dist/'))
});

gulp.task('default', gulp.series('sass', 'serve'));
gulp.task('dist', gulp.('dist'));