The Hiwassee comes out of the North Carolina mountains through a series of dams. That is why it runs cold in high summer and why its flow is a schedule rather than a season.
For a first-time paddler that is an unusually friendly combination. The whitewater is real and it is forgiving. The water level is knowable in advance rather than guessed at. Outfitters at the put-in will rent you everything and will put you on the water with a briefing.
The schedule is what catches people. The river at generation flow is a genuinely different proposition than the river between releases, and the difference is not subtle. TVA publishes the release times. Check them the morning you go, not the week before.
Two things I will say without softening, because the friendly version of this advice gets people hurt. Cold water is the actual hazard on this river, not the rapids. In spring and fall the water can be cold enough to matter if you are in it longer than you planned, and a life jacket that is buckled is the difference between an inconvenience and an incident. Wear it fastened, not draped.
Second, the section most beginners are sold is appropriate for beginners. The sections above it are not, and the map does not make that obvious.
The finished guide carries the release schedule, the outfitters, and each section rated for what it actually asks of a first-timer rather than for what sounds encouraging in a brochure.