“She gave me a look”
Here give someone a look means to direct a meaningful or reproachful glance at them. The professor silently expresses disapproval when Tina arrives late and sits down.
A2-54 / CEFR A2 / EPISODE 54
Explaining why you are late
SceneDuring a break in an evening university class. In the classroom, Tina tells Frank why she was late.

WORDS & CONTEXT
Here give someone a look means to direct a meaningful or reproachful glance at them. The professor silently expresses disapproval when Tina arrives late and sits down.
Earlier means sooner, and give you more time means to leave you more time to spare. Frank is not blaming Tina for the train delays; he suggests leaving early on rainy days to allow for delays. He does not claim that this will always prevent her from being late.
Just to be safe means as a precaution: something may not really be necessary, but you allow extra margin anyway. The real start time is 9 p.m. When Tina asks Frank to tell her it starts at 8 p.m. so she will leave early, Frank answers with 7:30 p.m., another thirty minutes earlier. He is not actually changing the start time; it is a joke to get her moving early. Because it is an evening class, all the times are p.m.