In places under the Terran Initiative's thumb (generally speaking, this includes anywhere humans exist) public schools are compulsory from grades 1 to 12. Grades 1 through 8 are classified as primary school. Grades 9 through 12 are classified as secondary school. Graduating from compulsory public school takes place when a person is around 17-18 years old. Public schools are still physical places that children attend in person, though some of their lessons may be taught using matrix datajacks and educational software.
If there's an exception to compulsory education in Initiative-controlled places, it would be Mars. Martians are hard to dictate things to at the best of times, and they have never really had a "best of times." Martians may want to educate their children of their own volition, but the curriculum is less structured than in other places - one Martian parent might think all their kid needs to know is how to raise brahman or work the mines. Another might think history or math are vital. The Tharsis colony has public schools that people may or may not send their kids to, and the majority do. Regardless, a not insignificant amount rely on home schooling, and function is valued over fluff.
Wayfarers would have some formal education that may or may not have concluded with graduation from a secondary school. Outsiders would have zero formal education. That's not to say they have no education at all, but it would depend very heavily on their specific circumstances.
Proles who attend university will have had incredible marks in compulsory school and, unless they have somebody looking out for them with a lot of money, got to go solely through scholarships that they earned through extremely hard work or talent. Proles with college educations are not the norm. If they continue to attend school after secondary (which is still outside the norm) it would usually be a vocational school.
Corporates who attended university are the norm for corporate citizens. They graduate secondary school and usually go straight into the university of their choice. If they didn't earn a place based on their performance in compulsory school, they can usually get in by supplanting with elective class credits. Corporates are a high priority for university recruiters. Though monetary concerns usually aren't a problem for corporates wanting to attend university, they earn their admission by performing highly.
Peers who don't have a college education are almost unheard of. They don't have to do much of anything to get in and they don't have to do much of anything to earn whatever degree sounds good to them, often with special honorifics attached. Most peer families don't have to pay for their children to attend, as their families' donations to this or that university or their long history of attending the same school across generations affords them more than a small degree of favoritism.
Terran is the first language spoken by all human beings, regardless of where they come from. Most major colonies and settlements have developed their own language over time and natives from those places typically speak their regional parlance fluently, but this is never at the expense of learning Terran. Labels, goods, software, signage, and formal documents are all prepared solely in Terran.