CCS/TMS320F28335: GUI Composer V2 : F28335 waiting for data...

If you select the target communication setting as USB UART as you have done, then you need to also modify your target application to support one of the available models - Monitor or Streaming. Otherwise no data will be received by the host.

Please see this link for more details on these communication models: 
https://dev.ti.com/gc/designer/help/GC_UserGuide_v2/targetprog.html#usb-uart

An alternate method is to use XDS JTAG transport. This method does not require any modifications to target application and it will use the JTAG connection for data exchange. https://dev.ti.com/gc/designer/help/GC_UserGuide_v2/targetprog.html#usb-xds

There is a F28x example tutorial that uses XDS transport available here: http://dev.ti.com/tirex/explore/node?node=ACuj7Q0odqsz7xV.GhI98w__FUz-xrs__LATEST

Hope this helps.