Just as another general matter, peak meters have little to do with loudness. There are many ways to raise the average level of your soundtrack mixes, make them louder, but they “can” be damaging to the overall sound if done incorrectly.
Anyway, peak meters don’t tell you much more than how much room you have before digital clipping. Vegas, oddly enough having started as an audio app, doesn’t seem to have RMS meters but you can use a third party plug-in on the master for that.
Here’s a free one… https://www.sonalksis.com/freeg.htm