How to fade a track?

Are you using the MASTER BUS as your output or is each track set to the output?

If you're using a bus, then you need to create a volume envelope on the bus and create nodes which resemble the volume fade that you want.

right click on the track, select ENVELOPES>TRACK ENVELOPES>VOLUME
create nodes by right clicking and select ADD NODE, or by double left clicking. move the node by dragging it.

if you're using individual tracks, then you'll need to fade each track either using the volume envelope of each track, or by using the fade tool. The fade tool is accessed by placing your cursor at the end of the track and moving it around slightly until you see a small triangle, then click and drag to make the fade appear.