First clue: the upperclassman you should follow has probably been named a captain by her coach, for good reason.
Second clue: the upperclassman you should follow spent significant time on the bench as a freshman and sophomore. She wasn’t highly recruited out of high school, and she’s had to work hard to see playing time.
Find an upperclassman that fits this description. Watch what she does, then do those same things.
Freshmen very often look to the fittest athlete on the team, even though the fittest athlete doesn’t necessarily train properly for her sport. They also look to the most talented athlete on the team, even though the most talented athlete might not train at all.
In that case, you’d be better off drawing a name from a hat.