not have the first idea about something (also not know/understand the first thing about something)NOT KNOW to not know anything about a subject, or not know how to do something 对某事一窍不通[一无所知] I wouldn’t have the first idea about what to do in that situation. 我若遇此情形就会无所适从。
I don’t know the first thing about cars. 我对汽车一窍不通。
→ not have the first idea about something at first1(12)