Depending on what kind of camcorder this video came from, you will not likely be able to edit it in Premiere Elements in its native form. (Flip camera video, can't be edited in Premiere Elements because it uses a proprietary compression system that most video editors can't read.)
But, if you can get it into Premiere Elements, place the clip on the timeline, right-click on it and select Delete Audio.
Meantime, if you'd like a good introduction to the program, be sure to check out my free Basic Training for Premiere Elements tutorials at Muvipix.com. I also offer a series of well-received books on the program. They're available on Amazon.com and at the Muvipix store.
On the conversion question, as Steve points out, it depends. Some formats/CODEC's are easily Imported, and the Exported/Shared to other formats/CODEC's, but with some footage, the Import will not succeed. There are many pure conversion programs, that handle a far broader range of input and also output. What are the specs. of your particular source files?
For removing Audio, there are several methods to do that in PrE. Steve has listed one simple method. Another is to just ignore the Audio and Export/Share to a Video-only file, and another is to open the Audio Mixer (Window>Audio Mixer) and choose Mute for that Track. A variation on Steve's method is the Alt-click on the Audio, and just hit the Delete key.
PrE, like most Adobe programs, offers several ways to accomplish the same end task.