A scalpel can be used to nick the skin to provide access for a scissors. Once that is done, there is really no need to ever again use any instrument more dangerous than a scissors. In order to dispense with the razor blade and scalpel, it probably helps to have small, sharp, fine pointed scissors. The FPDG is deliberately designed so that the text describing a structure can be read without turning away from the page with the illustration of the structure. Once you have read the directions, ask questions if any seem obvious.
Occasional mistakes are inevitable, and part of the learning process.
If you make a mistake, you can always ask to see other specimens for better examples of structures. In the case of paired structures, you may want to look on the other side of your specimen. Even if your dissection goes well, look at other pigs regularly. No two pigs will look exactly alike. This is partly due to differences in dissection technique, but mostly due to natural variation in the structures of two different animals of the same species.