For simple fade-in/out, gain and pan, you can drag the handles in the upper left/right corners of each sound event. For precise adjustments, right-click an event and select “sound event properties”.
If you want more advanced curve automation of level and pan, then use the track right-click menu and select “automate parameter > level/pan”. After that you can use the pencil tool (or double click with the select tool) to draw curve sequences and use the curve editor, or you can use the parameter faders in the mixer to create the curve sequences.