拍照 (pāi zhào) is the standard, everyday verb for 'take a photo'. It is a separable verb (离合词), so you can insert aspect or measure words (e.g., 拍了一张照). Its closest synonym is 照相 (zhào xiàng, also HSK3), which appears in fixed terms like 照相馆 (photo studio); 拍照 is more common in daily speech for casual photos. For formal photography, use 拍摄 (pāi shè, HSK5).