Thank you all for your advice. You've all made such good points. That's why I come here with my questions!!! hahahha.

I have several concerns about attending. Most importantly is that I don't want to cause an uncomfortable situation for the family. They have been asking to meet me for a couple of weeks. I don't want them to feel in a time of sorrow that they need to make "nice" with me. However, I will heed the advice given here and just keep the casual talk to a minimum.
Also, having just lost my father, I know that this day is a very personal one and one that you never forget. You share an enternal bond with the people that support you on that day....so hopefully the people that attend the service are people that will be around for a long time (not sure that I will be in this situation). I have no problem attending as a supportive "friend" since I've known him so long.....it's just that the affair is private for family only....that's what makes it so awkward.
Thanks again for all of your advice. I have decided to go and YES, I will dress appropriately....hahahhaa.