Cav can feel free to answer as well, but since I've been active duty for over 6 years, I figured I'd answer as well.
If you are referring to dependents, most assignments in the military are accompanied (i.e., your dependents come with you); however, there are some that are not. Typically the ones that are not are training assignments fewer than 20 weeks in length or short unaccompanied tours (e.g., a 12 month tour to Bahrain would be unaccompanied, but taking a 36-month tour would be accompanied). This includes PCS for internship/residency. They will move your dependents with you.
If you are referring to your parents or any family who are not dependents, you should absolutely not join the military if you do not want to be separated from them. Because you will be. Often. I've been in the Navy for 6.5 years, and I'm a 3 hour drive from my parents and have been for the last year and a half. That's the closest I've been to them. The other 5 years, I was no closer than a 4 hour flight and at one point was a 10 hour flight from them. That doesn't include deployment, when I was on the other side of the country.
This is not to say that you're not prepared for that, but I wanted to make sure you're aware the the military will move you all over the place, possibly even out of the country. I don't know many people who have been able to stay close to home for very long or at all. But that's part of the adventure. I've been to and lived in places I never thought I'd even visit. It's been awesome.
Cav will probably know more specifics about the match. Here are a few links where I've read about it:
How the military match works (as of 2014)
https://mccareer.files.wordpress.co...ard-application-procedures-signed-29jun18.pdf (section 8.a.-d.)
