...You don't! First things first - each xpac is a standalone experience, so you *can* play Path without HoT. But if you're wondering if Path of Fire still needs gliding or stuff like that to enjoy, the response is also negative.
The areas have being designed with mounts in mind, so, if you're still reluctant because of that, don't worry.
Gliding is still useful, ofc, but it's not necessary, and I've rarely used it so far. The only thing from HoT that I'm still using is my Daredevil.
Game on, champions!