Sidd might be TN for now idk
G-Good
E-Evil
L-Lawful
C-Chaotic
N-Neutral(can mean neutral in the good-evil scale or in the lawful-chaotic scale, with TN-True Neutral being both)
there's alot of discussion on what qualifies someone to certain alignment but if you want to know more
https://tvtropes.org/pmwiki/pmwiki.php/Main/CharacterAlignment
i guess that's as good oportunity to elaborate in my interpretation of the main characters alignment
Artemi-first she is a paladin which are obrigatory LG, even if she wasn't a paladin she's still a Good person who cares about protecting the inocent and helping those in need, she also cares greatly about honor,laws and authorithy which is very lawful
Coli-while he is not a bad guy he also doesn't go out of his way to anyone else either(exept his father) so neutral in the good-evil scale, he also constantly lies,cheats and steals to get what he wants and has no respect for the law or any external rule system, as wel as no code of honor, so i say Chaotic
Sidd-he is not evil by any means and his motivation of wanting to give a easier life for his parents, as well as just being a nice person in general makes me read him as Good, as for his lawful-chaotic aligment, he has no internal code of condute/honor that we know of, he has no problems following coli's order even when it involves breaking the law, and he seems to admire both the lawful church knights(i assuming by his reaction to meeting Artemi) and the chaotic bonebreaker guild so i would say he's Neutral in the lawful-chaotic sense
but that's just my interpretation anyway.