To be more specific, each clip can have a volume (level) envelope that you can turn up or down for the entire clip, or draw precise automation if needed.
Check the Envelope Ribbon tab and make sure the Volume Envelope is showing. You can also choose if the envelope is before or after any Clip FX.
Also, in the Clips Tab, there is a way to manually enter a gain change. See screen shot.
Finally, you could use the Meta Normalizer in the montage to get all the clips in a montage set to the same loudness with a variety of variables and options. It’s not always perfect but it’s usually very close and you can fine tune by ear from there.
