Im VERY new to fluent 6 (any version for that matter) and I am presented with a problem where I must find the time until a given temperature is reached in a 2d pipe cross section. Viscous fluid properties suggest cfd analysis rather than lumped heat capacity method. Any advice would be very much appreciated. Thank you

If your pipe flow is fully-developed, you can integrate the radial temperature profile quite easily. Set up your problem in a spreadsheet.

If your geometry is complex and flow undetermined, use FLUENT. Start with the tutorials. I would advise taking the Fluent training course.