workers vs jobs using Sidekiq, Redis, Whenever and ActiveJob Rails 4.2

I am a little confused as to where "jobs" and "workers" fall in the workflow of background processing. I'm trying to write my first rake tasks that send periodic emails and almost all tutorials are pre-rails 4.2, and so they suggest I create a Sidekiq worker, etc....though now, that Active Job is rolled into Rails 4.2...I think I can just create a Job...am I correct? I am using Redis, Sidekiq, Rails 4.2 and PG. I am using the Whenever gem for scheduling

Here is what I am doing to create these recurring emails:

send_test_job.rb

class SendTestJob < ActiveJob::Base
  queue_as :default

rescue_from(StandardError) do |exception|
    notify_failed_job_to_manager(exception)
  end
 # perform(users, project_archives, rakelogs, projects, user_archives)
    def perform
        @users = User.all
        @subject ="Test Email"
        if   @users.present? 
            AdminNotifierMailer.hourly_roundup(@users, @projects, @subject).deliver_later
        else
        end
    end

 private

  def notify_failed_job_to_manager(exception)
    AdminNotifierMailer.job_failed(User.find(?), exception).deliver_later
  end

end

scheduler.rake

namespace :admin do

    desc "sends a test email"
    task :send_test => :environment do
        puts "sending Test Job"
        SendTestJob.perform_later 
        puts "done"
    end

end

config/schedule.rb (for whenever gem)

every 1.minutes do
  rake "admin:send_test", :output => {:error => 'error.log', :standard => 'cron.log'}
end

sidekiq.yml (the code hinting color on this is screwy...so this may be an issue)

---
:concurrency: 25
:pidfile: ./tmp/pids/sidekiq.pid
:logfile: ./log/sidekiq.log
:queues:
  - default
  - [high_priority, 2]

As you can see I have no workers...but that's because I can't really figure out where to put one or if I need one.