What exactly does it mean to be sexually active? 1-2x per week enough or should it be daily?

Various meanings: Usually "sexually active" only means the person is having sex with another partner (or more than one), usually with intercourse or oral sex (i.e. not just petting, mutual masturbation, etc). Frequency of sex doesn't mean much. 1-2x weekly is pretty normal and average for monogamous couples. It can mean more frequent sex than average or multiple partners, but usually doesn't have this meaning.