I volunteer through Big Brothers Big Sisters.
@frugalfoothills or anyone else, send me a PM if the below isn't enough or you have some more specific ?s. I'll try to keep things general here... I will add that I feel super guilty about writing this as I haven't seen my lil bro in about a month.
My kid is a freshman, we started last year when he was starting 8th grade. At that age, sometimes kids just need a male/female in their life that's not their parent. My brother has 4 younger sisters and a step-dad who doesn't spend much time with him and/or travels a lot for work. Bio dad isn't in the picture, unfortunately. So really he just needed a bro to hang out with and talk to about life and school. That's pretty much all we do, eat together, walk around and go to the park, talk about classes, grades, girls (respectfully, duh), sports, other guy stuff. He doesn't get much of a voice at home despite being the oldest just because there's so many kids (and dogs) that it must be like a freakin circus living there. When we hang out he talks nonstop as if he doesn't get a chance to be heard anywhere else. Oh, I should add that this kid's family is easily upper middle class. That was a big surprise to me, I was expecting a lower-income family. However, due to the above stuff and having some high-functioning or not noticeable things like autism and ADD, an older brother was helpful. It's not only lower-income kids that could use a cool mentor/role model. They expect you to be with the kid for at least one year and generally speaking, see them every other week. I used to only text my bro's mom but now that he's in HS we text each other (still awkward rn). We generally stay around his house/neighborhood except for big occasions but may explore hanging around my place if everyone approves of it.
The application process is very in depth. Moreso than any job application I've had (more than my fair share for my age). You'll be asked plenty of personal things (sexual behavior, religion), so if that's a problem or "personal" to you, I would stay away. However, it's just that the parent wants to know who this rando will be. Plus I live in the south. So, maybe a straight white Christian male was important to the parents, or maybe everyone is asked those ?s, Idk. You have to provide references also. Oh, you have to have a casual interview with a BBBS person. I just met a girl at Starbucks and she asked me easy interview ?s as well as some of the awkward things listed above.
After you're approved is the matching process. They ask your preferences or if you care about age, race, high- or low-income, and geography of the kid. After they have one or a few possible matches, they tell you all about the kid to make sure you're ok with all of the potential hangups. For example, I was told my kid had high-functioning autism and ADD, but that he was also in all of the normal classes and had good/ok grades depending on the subject.
There is a big BBBS network. Helpful site with recommendations, deals or free activities, sponsored big fun things (more for little kids). I have an official BBBS person that calls me and asks not only if I have needs, but to document specific hours and activities for donor and nonprofit tax and tracking purposes. It's very official and legit. Reminder to self, I need to explore tax implications...charitable giving, anyone?? Need to check out the BBBS site for this, completely forgot about it for taxes last year.