I am looking to buy a car and do not know what some jargon means, like what to look for e.g. MPG or BHP, so I was wondering if there was a stack that can answer my question pre-buying.
"What to look for" sounds like an unclear question, since it will depend on a lot of things (e.g. your budget and your location). The site does have some questions about buying a car, but a lot of them are closed (there have probably been more questions, but they might be deleted after a year).