Torrey is remote. The nearest city with commercial flights is Salt Lake City, about 4 hours north on Highway 24 via Interstate 70 (the western section of I-70, around Salina, is worth a look — it crosses some of the most dramatic canyon country in the US). There is no public transport to Torrey. You will need a car.
From Las Vegas, the drive is about 4.5 hours via I-15 and Highway 20. From Bryce Canyon, about 1.5 hours north-east via Highway 12 — a scenic road that is one of the best drives in Utah in its own right. From Moab and Arches/Canyonlands, about 3 hours west. Gas up before entering the park or in Torrey — the next stations are 80+ miles in any direction.