My engine clicks loudly on cold start for about 30 seconds and then quiets down. I was told it was injector noise and was fine as long as it stopped, but it is really loud. Is this something I should worry about or have checked?

Welcome to AF. That noise you describe wouldn't be injectors. They do make noise but not to the extent of your problem. I would suggest that the lifters aren't pumping up until the engine has run for a while. If you live in a cold climate they will talk to you until the engine has run for a while. I would suggest changing to a lighter oil that will pump the lifters up faster. Change the oil and go to a 5w-30w weight.

factory oil is supposed to be 5W-20...