I download the trying version of Indesign CC and I can't find the folio builder... How could I find it?
Should be in the menu, in "Window". Not there?
However, the folio builder uses the DPS, which is most likely not part of a trial version, nor installed by default with a retail version.
InDesign CC2015 does not support folio workflows and DPS Classic. Only the new Digital Publishing Solution is supported.
For folio workflows you'll need to use CC2014