In order to install module, you can do it two ways:

Install By Composer
    Take clone
    run composer require sbdevblog/module-sbdevblog-crons
    Run necessary magento commands like setup:upgrade, di:compile, static-content:deploy
Install From App/Code
    Clone and Just extract zip and paste SbDevBlog/Crons directory inside app/code
    Run necessary magento commands like setup:upgrade, di:compile, static-content:deploy

Command to run cron:
    php bin/magento cron:run

Run specific group
    php bin/magento cron:run --group=GROUP

Create a custom cron by clicking: https://sbdevblog.com/magento-2-create-custom-cron/

Create a custom message queue by clicking: https://sbdevblog.com/magento-2-how-to-create-a-message-queue/