When you run the file "CC_Pipeline_Extension_Trial_Hub.exe" this will install the Reallusion Hub which is used to install all trial and full versions. Installing the Hub is very quick so it may have been installed without you realizing.
Please check your Desktop (or Start Menu) for the Reallusion Hub. If you have an icon for it on the Desktop just double click it to open the Hub. Once open, sign in with your Reallusion Account details and then you will have the option to install trial versions of all our products including Character Creator 3.
If you don't have the Reallusion Hub installed yet, please download and install it from page below.