Mind you, the manual could be written better.
Since you can get to Satellite Setup, use the left /right keys to select satellite or a blank space.
If it's an 'existing' satellite, then you'll see the signal/quality meters move (so long as the dish can 'see' the sat correctly). If it's a new satellite then first press green to name it, then enter all the parameters for that sat (again, the dish needs to be able to see the sat correctly)
Make sure you have the correct LNB type for the sat you want to see.
If the signal/quality meters are showing good levels (about 70 - 80% preferably) then hit red - this will begin the satellite scan.
With things like 28East, the preset options are OK, you shouldn't have any problems picking up a good signal - again, make sure the dish is correctly alligned. New (i.e. sats not in the internal database) will probably need a bit of research. You might also find that new sats are simply too far east or west to see - or that there is something blocking line of site with the sat you want.