Okay so, the first character you create is up to you right? and I think you start with access to some mutations and stuff. Is there any way to use the Generator again or gain back those points that you used? I feel like it's a stupid question and it's probably bought with diamonds or something, I just wondered if it was actually a thing to create more than one character. hh I created my first one like a year ago and I would really like to make an updated version of them and gAH idk

If you mean the Generator, any sylesti you create can have any traits that the species has (excluding Restricted traits, which should appear in red text rather than black, but sometimes they don't show that, but there's a full list in the guide we linked).

To use the Generator, you need Essences, and we have a full guide to essences- what they are, how you can get them, and how to use them- right here.
But no, Diamonds aren't necessary to get Essences (with the exception of Mystical Essences, but people do occasionally sell those on the Broker)- Both Regular and Enhanced Essences can be obtained by chance for free (as covered in the guide)

Pets made in the Generator cannot be given new traits- they're stuck with the Trait Point Count, and Traits, that they started with. You can use pet dyes on them, though.
The only exception is if the pet existed prior to a revamp of their species, and, due to trait alterations/shuffling, are made eligible for Regenning (covered in post 3, "Section 7; Bonus Section 1 Regennable Pets" of the Essence Guide) (Vulnyx have already been revamped, and were revamped before Regens were a thing in any case.)

Ah I looked at the post about it and with your comment I understand now.Thank you!