Last but not least, the easiest way to keep score is to use any score card from any golf course. That way you already have all the pars, and it will dictate what holes are going to be par 3's (for semi-pro and pro).
     Now if you don't have a score card you could use the example I have. It is blank, so you can put your own par 3's wherever you want, (two par 3's on the front nine and two on the back nine).