How do I volume down or erase loud noise in a clip

If you want to reduce the volume of one portion of the clip, you can select the clip you want to reduce and then lower the volume controls under "Effects Controls."

Hey - If you right click on the audio file in Premiere and select "Edit Clip in Adobe Audition." Select the noise you want to remove in the audio clip, then go to Effects > Noise Reduction / Restoration > Capture Noise Print. Then go back to Effects > Noise Reduction /Restoration > Noise Reduction (process)... Be sure to "Select Entire Clip" in the new window. You can play around with the noise reduction levels until it achieves your desired outcome.

If you want something easy and fast, depending on the noise and if you work on a MAC, you can use a for purchase plugin called "CrumplePop Audio Denoise." I use it a lot when I have a fan noise or hum in the background I need to remove (like A/C/).  Here is a tutorial > How to Remove Audio Noise in Adobe Premiere Pro 2017 - YouTube

This might be better done in Audition.