No Coax hookup: Older mobile home

Just had to come back home from living in another state, didn't realize there wasn't a coax feed into the trailer as the interent from before was powered exclusively through CAT cables and run up to a dish of some kind. I was doing some research and it looks like the connections aren't how they used to be where if you spliced into another line it was effectively stealing, but with the connections now being tied to the equipment and account of the modem itself, is it possible now to install a splitter at a family members home, to run the coax cable a space down, and not be an active menace? Or am I completely wrong and its still just jacking their connection. Neither of us know, and neither of us wants to A. Steal and B. ruin quality.

Perhaps it would just be best to wait on a tech to come out and install/reinstall/fix whatever happened to the coax connection to this home.

Already paid for service, picked up the gateway at the xfinity store, just [Edited: Language] for the time being without a way to hook the darn thing up, and it would be significantly faster to buy a 50 foot cable and a splitter.