"Is it true that there's no road to Juneau?"
It's true! There are no roads that go to Juneau. You have to get there by ferry system or by plane.
From Seattle (2 hours) or Anchorage (1 1/2 hours), you would be best using Alaska Airlines. From nearby cities such as Skagway, Haines, Gustavus, etc., small commuter planes are available.
The Alaska Marine Highway System or a charter company could be used.
Once you're in Juneau, the road system is adequate and there is a main highway approximately 45 miles long, known as Egan Drive, that follows the coastline.
Juneau image courtesy of alaska.org