Yes. You'll find many people simply put on some 'clip on' aero bars to a road bike to start off with. Many TT with a road bike frame to which purpose built aerobars are on instead of 'normal' drops with clip on aeros. Disc wheel - on the rear only. Many use a rear disc and front deep rim.
For a long time my son used a Cervelo Soloist frame, Pro Missile bars, Zipp Disc on rear & Zipp 404 on front. If it was very windy, he'd run a Zipp 404 on the back instead of the disc.
Here you go:-
www.ctt.org.uk
The thing with time trialling is you can do it to whatever level your ability/interest lies. You can spend oodles of dosh on a TT-specific bike and carbon bling, or you simply use a road bike as is. You can work at it to be *the fastest* or to get fitter over time by keeping a note of your times on a specific course and get as fast as you can. In the prizes stakes, there's often 'scratch' for overall fastest, handicap prizes - to encourage the less speedy, and age-related prizes.