Being confident in what you’re wearing can really be the “be all, end all” of an outfit. If you aren’t confident with what you’re wearing it can really show! However, confidence is not “they will like my outfit!” Confidence is
“I’ll be fine if nobody likes my outfit, because I love my outfit!”

Here's a tip to help you feel more confident about either yourself
or your outfit:

Go stand in front of a mirror (full length mirror, if possible) and take a good look at yourself. Then pick out 5 different things that you love about your outfit (or your body). Say these things out loud if it'll help you more, sometimes saying things out loud makes them feel more permanent.

I love my eyes,

eyelashes,

hair,

the freckles on my shoulders,

and the shape of my lips.