Nine if fine. You don't need a .45 to be safe, a 9mm will do the job just fine. I love how a vast majority of new shooters want something big... Too big. The perfect example was a guy I gave a lesson to today. He had a brand new gun, has had it for over six months, but never fired it. He didn't even know to to hold the pistol correctly, get a correct sight picture, nor stand (Let alone the small things, like trigger pull, reset, breathing, etc.). It was alright though, because if he needed to, he would blow that bad guy away with his big ole' American .45ACP... If he knew how to rack the slide... After a good hour or so of working with him, the paper went from looking like Swiss Cheese to actual, noticeable groupings. Hell, at least I got to shoot his S&W M&P45, I've been waiting to play with one.
Don't be afraid to get a nine. Nobody is going to call your weapon puny and to popular belief, a group of evil ninjas will not jump out of the bushes at night once that get word that you're carrying a smaller caliber. With a nine, you have the ability to shoot more and for a whole lot cheaper. Another thing new shooters are worried about; speed. Don't, you should shoot slow and steady for the first year, time will come for the blazing later. Speed is fine, accuracy is fine.
I'm a huge Glock fan, I would highly recommend the 17, 19, or 26. The 17 is argumentatively the best full size, nine millimeter handgun out there for the money. If you plan on getting something to shoot at the range and for protection, get a 19 (They're hard to find right now). If you want something really small to hide if you need be, the 26 is great. I call mine Houdini, he can easily disappear in my pants. With a grip extension for the magazine, you can easily have fun at the range with it also.
Yes, there are other great handguns out there. For nine though, it is very hard to beat the Glock. For larger calibers, I'll be the first to admit that there are better choices to be made. I also recommend Springfield Armory's XD/XDM series for new shooters. Some people just prefer one grip angle over the other. If you're going to buy something, try to rent the same model or find a local with one, just so you can actually see how it performs in your hands. Gosh, I love this expensive hobby, it is worse than a drug addiction. Time to start piecing together an AR, just to compete in 3 gun competitions. Stay safe and have fun.