Wizard: Starting with Immortality

The protagonist makes mistakes = The protagonist will definitely make mistakes The protagonist will be schemed against = The protagonist will definitely be schemed against. Judging from the description, are you planning to rewrite this as a classic storyline?

There's practically no barrier to entry for wizard-themed immortality stories, so it's unclear what the point of writing such stories is.

Let's change my name. I, who am immortal, choose to be a nanny forever... Disgusting.

There's a curse involved, so they've run away. Doesn't Western fantasy already have its share of tropes? Adding a curse like that just doesn't fit my style.

An immortal being bound to a natal Gu (a type of magical insect) for life and death—don't you think that's rather abstract?

An immortal being acting as a babysitter for someone else? That's amazing!

The cheat ability is immortality, which isn't inherently wrong. The fast-paced opening plot is an attempt to compress the endlessly drawn-out apprenticeship period found in other wizarding novels, quickly leading to the formal wizarding stage.

Writing about wizards achieving immortality is difficult because, in my experience, the wizard cultivation system is incredibly life-extending. They don't even need to reach very high levels; even in the early stages, they can easily live for hundreds or thousands of years.

The protagonist suffered a setback as soon as the book was released, awesome!

It's too much of a hodgepodge. Either write a proper Western fantasy novel, or just write a Xianxia novel directly. These jarring plot points keep popping up, like suddenly finding out in a traditional Xianxia novel that a sect leader has broken through to the Omega level of cultivation. It's really uncomfortable to read.