Double click on a chart to edit data and change chart settings.
You can copy-paste data to the spreadsheet or load your own Excel or CSV file. If you want your data to be automatically updated, use "Load data" and then "Connect live data". Read about real-time data here. Pay attention to each chart data structure - organize your data as shown in the preloaded example.
Each chart has different settings. You can find settings above the spreadsheet.
Change chart colors in the second tab of the chart settings panel: