Your cell signal doesn't look very good -- is that at home? Poor cell signal can drain the battery (even if you're connected to wi-fi). You could test to see if the poor signal is the main cause of drain by testing it in Airplane Mode (but you can still keep wi-fi on and use wi-fi calling).
Also, since you just got the phone yesterday, keep in mind that (a) the first day of a phone is often a big battery drain, as you're installing and updating a ton of things (including the system), and (b) the system is still learning your usage pattern over the first few days, so battery life can be unsettled during this period.