Yes there are. It can be any combination of who swims, bikes and runs. I competed in one as the swimmer, and had a different runner and biker. There was one team that only had 2 members, one swam and the other lady did both the run and the bike. Sinc...
Here's a list of "standard race distances" for a triathlon: Here's a list of "non-standard variations": The standard race distance for an Olympic triathlon, for example, is: 1.5 km (0.93 mi) Swimming, 40 km (24.8 mi) Cycling, 10 km (6.2 mi) Running
If you're in this to have fun, I would not spend big dollars on a bike this time. If you enjoy it and think you may do more you can always invest more money down the road. I would purchase a pretty standard road bike. This type of bike will give you ...