The trial version does not support anything MPEG as is explicitly stated on the Adobe website. So you need to convert to MS DV AVI type2 before import. Use Google to find a suitable converter or search here. It has been discussed hundreds of times.
You will not be able to Capture from the HDD camera in PrPro. As Harm mentions, if you have the trial, you cannot do anything regarding MPEG.
You will need to copy over the .MPEG (not sure if it writes this as a .VOB, or a straight MPEG file, to your computer, and then convert that/those file(s) to DV-AVI Type II, and then Import that/those file(s), into PrPro. I use DigitalMedia Converter, but there are free conversion programs that do it too, like Prism. Then, you will edit, and Export as DV-AVI to be used by an authoring program. With the trial, you will not have Encore, Adobe's excellent authoring app. Still, there are many others, that work, though not nearly so well. I think that Roxio, Nero and CyberLink have some authoring capabilities in certain of their programs. I do not use anything but Encore, so do not know how well, or poorly, these other programs function.
PS - if the other camera records to miniDVD, or uses the .VOB container, this ARTICLE will give you some background on that "format."