Heya! Depending on your needs, there's a large amount of free visual novel resources out there if you felt at the current time you didn't have the funds to get art.

https://itch.io/game-assets/free/genre-visual-novel

So you could focus on the writing and practicing with coding, and pick the assets you felt matched your vision the best! Though if you're planning on selling what you create, it's best to read the terms for each asset pack to ensure it's okay.