I personally despise (at least most of the time) when the author introduces a character as your best friend, because half the time I end up disliking them, and the other half of the time, it still feels weird. And it’s even more bizarre to have the MC decide the supporting character’s personality and whatnot.
In my WIP, The Magician’s Task, there are about a dozen main characters, and most of them begin as acquaintances or family members. From there, I just let the MC form their relationships with these various characters as they go. Even with your family, I don’t assume that your relationship with them is good, and I allow you to make that decision on your own as you get to know them through the chapters.
The only character who I made automatically have a very bad relationship with you is Killian, a guy who is basically the antagonist of the first three chapters, and who has been tormenting the MC for like 10 years. And even then, I’ll be giving you a chance to try to improve your relationship with him throughout the series (or let it alone, or be bitter towards him, etc.)
I do enjoy having good physical descriptions of the characters so that myself and my readers can picture them easily and create stronger connections to those characters. Although my favorite book series ever, Chaos Walking, has amazing characters, it has a gigantic flaw in that the author practically never describes any of the characters’ physical traits in any way and it’s super irritating.