Once you're in the Designer, a good first step is to create some tags. You'll use these tags for realtime status and control and to store history with the SQLTags Historian.
Drag-and-Drop from OPC
If you created a device in the earlier step, the easiest way to create some SQLTags is through drag-and-drop. Select the "Tags" folder, and then click on the device icon to bring up the OPC Browser.
The OPC browser button
Now you can browse all of your OPC connections. By default you've got a connection to the internal Ignition OPC-UA server, which has the device in it that you created earlier. Browse the device and find some tags that you're interested in. Highlight the tags and drag them into the "Tags" folder in the SQLTags Browser panel.
Creating SQLTags from the OPC browser
Thats it - you now have some SQLTags. You should see their values come in and start updating.