weddings, anniversaries, & reunions are a huge hit these days. if you find one person and do it for free you automatically have a portfolio. i recommend buying photoshop or some program with equal options. read the instruction book first, there is a lot more than you know in those programs. if you dont know anyone getting married, dress up your friends and take all sorts of pictures. from artistic (id love to help but thats all interpretive) to traditional. digital is the only way to do this well, so invest well. high resolution is very important..try to avoid any cameras with a video option, they tend to eat batteries and impede on the cameras performance.
as far as the job....make sure you ask tons of questions of your client. make a list before you go....everything from what color outfits are being worn to the venue. be prepared for everything to go wrong, bc you never know. also make sure they are aware of the photo process. many people do not realise to get a good picture you need to be close to the event. weddings, for example, you need to be close to the altar. you can do this without being seen (hide on the side) but if they want artsy views you will be seen. dress up! always wear a neutral color (even black) that wont stand out of the crowd. communication is the best way to have great clientelle reccomendations. after that, its all learning on the job. good luck. i hope i helped a litte.