In pure UE4 you can do this only via C++, in programming raw TCP/UDP network communication is usually called “sockets” (don’t mistake with HTML Sockets which work bit different with incorporation of HTTP) so search using that name
UE4 has dedicated module for raw network communication called (supprice) “sockets”, here API refrence:
Here oyu got some use examples from wiki
If you plan using HTTP, UE4 has also dedicated module for that so you don’t need to use raw TCP communication for it, here anwser that i posted in past showing how to use it
and i know UE4 plugin called VaRest which enables HTTP communication in blueprint with parsing included