So, you can move the printer manually using the controls in Repetier Host, correct? and you have the printer configured correctly in "Printer Settings"?
Make sure, on the manual control tab, that you have the "dry run" button turned off
not sure what version you are using, but this is what the "Manual Control" tab in v1.0.6 looks like
note the button on the bottom right..
Also, you do have to slice a file before you can actually print it..you can't just load a file and start...
Repetier Host comes with both Slic3r and Cura bundled in - you can choose which you want to use.
My preference is Slic3r, but it is entirely up to you which one you use.
there is a Configuration button that will open the control panel for whichever slicing program you want to use to set things like number of perimeters/shells, number of top/bottom layers, infill percentage, etc.