No, you don't have to find TDC to set the valves. Google some You Tube videos and it might give you some good advice and methods. Essentially, rotate the engine until one of the valves for a cylinder is well on its way down. Then adjust the other valve on that cylinder. Then rotate the engine so that you can adjust the other valve. Follow this pattern for all cylinders and double check them afterwards. Make sure you disable the engine from starting if you're rotating the engine via the starter.
Another method is to rotate the engine so that the cylinder is well into its compression stroke. Both valves will be closed at that time. This way, you can adjust both valves at one time. Then move on until another cylinder.