Welcome to the forum.
Here's how it works.
1. You find a girlfriend overseas
2. You visit her, and if she's "the one," you either marry her in her home country and file for a K3 (spousal) visa, or don't get married and file a K1 (fiancee) visa.
3. You bring her to the US
4. If you didn't marry her in her home country, you marry her here.
5. You live happily ever after.
I'm not being sarcastic. It's just that there are as many ways to accomplish 1, 2 and 5, as there are people posting on this board. We've all done it a different way. There are dozens of countries represented, and age differences from the wives being older to the husband being nearly 50 years older than the wife. (I've been in touch with that couple and they're still very much in-love after 6 years of marriage) Some guys say use the dating sites, some say use agencies, some say just hop on a plane and go, some say use others for introductions. We have guys who hitch hike to the airport and guys who take a limo, guys seeking dirt poor country girls to guys looking for city girls from wealthy families. Some of us are fluent in the language of our GFs or wives, some can't speak a word. It's all workable. We get in all sorts of arguments about which way is better, but the truth is that they all work, and they all don't work. There have been plenty of failures using every correct technique and plenty of successes using all the wrong methods. It all depends on you, your intentions, sincerity, ability to see through BS, and sometimes just plain old luck. Come on in - the water is fine.
Jeff