We all started at the beginning and then built on what we learn.

One of the most important lessons that you have already learned is that flights without points are a waste.

Like schmare said, quickly join the programs you need to claim miles for the trips you have already taken, but don't let them dictate which program will become you primary program. That needs to be determined by your home city and your most frequent destinations. If you feel comfortable posting your home city and your most frequent destinations, I am sure that lots of folks will be able to offer advice.

Good luck and don't worry too much about becoming an FT junkie. It doesn't really matter that your friends, family and co-workers will all think that you are crazy. You will get lots of support and encouragment on FT. There are lots of seriously addicted travelers here.