If you are limited to one gun, this is the single most significant key in deciding what kind it’s going to be. Consider your daily, weekly, monthly life and where a gun would be needed most, and you have your answer to what general type of handgun you should purchase. It doesn’t answer the question of best brands, accessories, etc., but it does stop the incessant, futile search for a “one gun solution”.
If you live in an urban (city) setting and your day to day work, play, visit paths take you to various parts of town and put you in diverse situations, that’s a pretty large percentage of your life. Compare that to the couple of times per month you go hiking for 5 miles through an area where there is a chance of encountering a bear. The obvious ratio should cause you to lean in favor of a gun that you would be capable of carrying daily, the way you dress, work and travel daily.
The bears should take a lower priority than your city travels because of the much less likely scenario of encountering them in a dangerous situation. It doesn’t mean that bears are not an important safety consideration, but the gun for city living and bear protection are generally going to be decidedly and significantly different.
The .44 magnum you need to protect you from bears, is not likely going to be the gun that is going to go well in an inside the waistband holster or a purse.
If you can only purchase or own one gun, look intelligently at the most likely and often scenarios in which you would need a gun for protection in your life, based on how you live and what you do 24/7. Your decision should not be based on isolated instances of what you might do. Make your choice for a gun on that basis, and you will have the right one for the way you live.
As for where to buy a gun or where to search for one – the best place would be the internet. You can find a reputable online gun dealer in your area easy. There are a lot of online gun dealers to choose from.