You can choose from a library of over 70 technical indicators. For more information on any particular indicator, just type the name into any Internet search engine and you'll find a ton of information on what they are, how they're calculated and how to apply them.
Click the Add Indicator button at the top of the chart to view the indicator library. Indicators are grouped into System, My Saved Indicators and custom Formulas.
Click on a category to expand it or just start typing the name of the indicator you're looking for and the list will filter automatically.
To add a child indicator like a Moving Average or Envelope Channels to another plot on the chart, click on that plot then select Add Indicator. The available child plots will come to the top of the list. This is also how you add another indicator to the same pane on the chart. Instead of selecting a child indicator, just choose any other indicator from the list and it will plot in the same pane with its own scale.