Greetings Gary welcome to the Forum :welcome:
Are you saying that your HDTV does not have a built in Tuner ?
Take a look at the Spec Sheet or look for the following labels on it...
If it has a Digital Tuner in it, it will have a label like...
HDTV
DTV TUNER
SDTV TUNER
HD TUNER
DTV-READY
If it does not have a ATSC Tuner in it, then these may be seen...
HD-MONITOR
HDTV READY
HDTV CAPABLE
Should the latter be the case, then you can purchase a Digital Tuner, or, I believe there are resources where you could buy the parts, and assemble one yourself.
Just in case you'd like to test your TV, you can buy/borrow a simple set of RabitEars or other Antenna to temporarily connect to the set, do a scan, and see if you can receive any Digital station. If you can, then your set has an ATSC/Digital Tuner in it, and you then can arrange for a more perminent acceptable Antenna System for it.
Have a good Day !

S.W.