iPhone 7 facing lot of issues suddenly

Hi,

My iPhone 7 was all fine for an Year almost. Now from few days,I have trouble making calls or receiving. Touch doesn’t work sometimes. My camera doesn’t work sometime even though I have memory available. For one whole day, it never turned on, it was just bright white with Apple logo and nothing worked. Feeling terrible after paying so heavy on this and not able to use.Appreciate any help, thanks!!