Obviously you can create your character however you please, but for those looking to create a character that is as true to the lore as possible for role-playing purposes, the following will give some useful guidance.
Packs are incredibly important to an Avali, representing far more than just family. Avali packs are inseparable and know the minds of each of their members intimately.
It's very easy when creating an Avali character to write off the other members of your pack and say your character is a loner, orphan, survivor of a disaster or other such excuse; but it's worth considering simply writing the pack as being off-screen. This will allow you to bring in friends as other pack members down the line if desired.
Avali that genuinely have lost multiple pack members often display serious psychological trauma as a result: panic attacks, delusion, compulsive behaviours, and other negative effects due to the trauma such an event has on the Avali psyche.
Does your RP setting have to take place in an environment where there are many alien species, or you want to mix in alien technologies and ethos that would never be accepted in the Avali illuminate? Do you want to play an avali with a background that isn't entirely consistent with the core lore?
Consider creating a new independent world of your own for the story. Narratively this is the main purpose of the independent worlds, to provide an in-universe platform to use the Avali, outside of their "usual" environment.
If you are not able to think of any story lines to stick to, consider implementing and combining aspects from the real world. What would happen if Avali's went to your favorite music festival? How would a show be different if Avali's were the actors. With so many combinations to make, the possibilities are limitless.
Like humans, Avali enjoy a wide variety of hobbies. Most Avali, however, count music as one of their interests, and commonly practice music either solo or with the rest of their pack. Having a preferred instrument (or singing talent) is a likely detail of Avali characters.
All avali have some level of augmentation, if only a neural jack and guardian nanites. However, some Avali have far more, such as replacement limbs, or even replacement bodies. Such cybernetics can be made to look as realistic as the original limb if desired, although some may opt to leave it visibly artificial.
Cybernetics in this regard can be a useful roleplay tool for explaining unusual abilities, whether they be technological skills, shrugging off how your character 'died' and yet is unharmed, or other unusual traits, such as wearing lightweight clothing or not wearing eye protection on a world that where Avali biology would prevent them doing so. Full body cybernetics can also allow Avali to survive outside of their normal habitat.
The most important thing to take away about any large, interstellar population is how diverse such a society would be. As one such society, the Avali are equally varied: there are nice avali and there are jerks, there are atheists and theists, there are merchants and there are pirates, soldiers and pacifists.
...there are even vegans. Yes, you heard right. Vegans.
(Don't get us started with the politicians.)