You should examine every box on the outside of your RV first for a screw-on coax connector... maybe they put them in separate locations for some strange reason. If the one you've found for satellite is not near your shore power connection then look for your cable receptacle there... when parks provide cable, their receptacle will be on the same post as the shore power and thus it makes most sense for the RV connection to be near the shore power input too.
I've never seen a recent RV that didn't have an exterior receptacle for both cable and satellite (if it had one, it had both). It usually looks like an the outdoor AC receptacle with a hinged plastic cover like this
If you have an antenna and booster then try to look at the back of the booster
and there should be 3 cable connections: one out to the tele (or a wall plate from where it is intended to go to the tele), one in from the antenna (selected when the booster switch is on and pilot light illuminated) and one from an exterior jack (selected when the booster is off).
You're saying you have only the satellite connection?
If it is double-width like the one shown above, but with only one connector, you could just buy a cable coupler
and drill a 1/4" hole to install it in the blank side. You'd then use a short length of coax to go from the inside end of the coupler to the 'cable' input of the booster.
If you have only a single-width receptacle like this
, you could either add a second one (probably only a 1/4" hole in the exterior required) or replace the single with the dual (may have to expand the cutout).
2015 Rockwood Signature UltraLite 8282WS Platinum, GY Marathon LRD, TST 507RV TPMS
2005 GMC 2500HD CCSB D/A, Curt E16, Prodigy P2, Garmin RV760LMT w/BC-20 b/u cam