I would like to apologize in advance for responding slowly.
> 1. Set the template about Sydney
Could you please try to follow the tutorial which is written here https://athemes.com/documentation/sydney/?
> 2. Installed the plugins that he demanded.
You should need to download the portfolio plugin. Then, from your Dashboard > Plugins > Add New > Upload and install the downloaded file (sydney-portfolio.zip).
For the other required plugins can be installed and activated through Appearance > Install Plugin menu
> 3.Activated the license about Sydney.
You should need to put the license key through Appearance > Theme License menu
> 4. Downloaded sydney-pro-settings and set it
Could you please try to follow its tutorial here https://athemes.com/documentation/sydney/#quickstart?
> 5. But can’t find the demo content exactly who Sydney pro
Where can I get demo content Sydney pro?
We officially don’t provide it publicly at the moment. Because differences aren’t that big compared to the free one. You can download the sample demo content of the pro version here http://d.pr/f/1cxVn
To setting up the Crelly Slider, please head on here https://athemes.com/documentation/crelly-slider/
I hope this reply helps.