I'm not sure I understand what you mean by "one of the first". Friendster got 1 million users before anyone else, and was launched 2002. PlanetAll launched 1996. SixDegrees launched 1997. Friends Reunited launched 2000. SuicideGirls launched 2001. MySpace launched 2003. LinkedIn launched 2003.
Social networking features were also common in many other communities.
I really hate when people claim they were first on something hoping nobody remembers what came before.
Disclaimer: I helped build one of the first e-commerce applications in Brazil - a supermarket mailed CD-ROMs to clients who shopped and an application sent a text file over the phone (it was 1994 or 1995, months before the first proper ISP launched) and a program on the receiving end would process everything. Payment was money or check, paid upon receiving the merchandise. The client-side was mostly ToolBook and the back-end was Visual Basic.
That supermarket was one of the first to launch a website a year later built upon the backend processes we helped build, but with completely new software. Later in 1996 I wrote the e-commerce site for Brazil's then largest department store. At 10 orders per day, it was a huge success. I usually say it was one of the first and I'm aware of 2 other stores that came before.