let's create a personality right now in this comment.
first we think a basis for the character it can be anything but let's start with one word: magic,
now we think of another unrelated word I will pick a mood, let's pick happiness,
the character is a joyful mage...
now we give an exception to that core emotion
.they are joyfull most of the time except when they see a dragon.
it can be anything.
now we give an explanation
dragons reminds them of when their whole vilage was burned down by a dragon and they were the only survivor.
they are joyfull because despite their trauma they decided to not let that weight them down
so they are fierce, strong willed, and never out of hope.
now we give some flaws.
they talk too much and can't foucus
a key is to with each layer add things not directly coraleted.
so far we have a strong willed joyfull fierce hopefull mage that get's sad when sees a dragon, talks too much and can't focus.
already we have an original compelling character, but that alone won't do for a main character we need to add more,
so lets do a complete backstory
they born in a simple vilage, raised by loving parents who were farmers unltil at the age of 8 a dragon atacked their parents fought to keep the character safe and sacrificed themselves with a smille, an smille that would be inprinted in the character's mind as an example of atituted toward adversity, the character survives but nothing is left of their vilage they decided to not let that put them down so they move on, and find a mage they become an aprentice to the mage and become skilled at nagic, their main goal with magic is bring their family back something that is said to be impossible except with the help of an artifact so they go an a jorney to get that.
and now not only we have a compelling character but also a basis for the story that is character driven.
it's not an exact science and a lot is up to your imagination but try to combine as much diferent ideas as possible and them jusfy them for the character and that is enough for a story I think.