You all ready have two green balls, so someone has been giving you reputation. Just click on the scales down near the bottom of a members post on the left. We used to be able to give negative reputation and some members would end up with red balls. Two where the maximum before that member normally got banned, but we did have one make it to three *cough* McTojo*cough*.
Infraction point are only given by mods and admin and the majority of members have never recieved them.