How much 自信 do you have that you know how to read this word already? I bet you have some, at least! This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
Koichi is quite the self-confident person.
You should have more confidence in yourself.
Viet said he was sure he could draw Koichi’s face better than anyone else because he knew him better than anyone else.