Graduate school life is much different from undergrad life. The stereotypical college experience that UT-Austin represents for a lot of people doesn’t really happen for graduate students, not in the same way. Ironically, I think new college grads who go straight to work have the closest approximation to that (still young enough to want to, but old enough to have money to finance that lifestyle, and a lot more free time than a grad student).
There are much cheaper ways to make friends…and you might be disappointed. Graduate students don’t tend to be looking for new ‘friends for life,’ either. (Of course, I will say it kind of depends on what you go for - many professional programs, like MPA, MBA, even some MPH programs are structured for the students to network and make connections, because that’s part of the learning.)
If you have a computer science degree, why don’t you try to get a job in software development at a U.S. based company? I’d say that my first couple years at my large tech company did feel more akin to undergrad, because most people move here from somewhere else and are looking to make friends.
I think what you’re thinking of is the OPT program for F-1 students (https://www.uscis.gov/working-in-the-united-states/students-and-exchange-visitors/optional-practical-training-opt-for-f-1-students), which allows eligible students to receive up to 12 months of temporary employment authorization in the U.S. In computer science, the OPT allowance is up to 3 years/36 months.