Stay away from cliches, but also realize that it’s okay if you can’t come up with something 100% original. I guarantee you that whatever you pick anyway will in someway be used in another book. Of course don’t plagiarize or blatantly steal someone else’s idea, but it’s totally okay to get inspiration! This goes for storytelling in general, it’s not about the “what” as much as it’s about the “HOW”. How you get from point a to point b of your story. What obstacles your character needs to overcome and how it makes their mission difficult.
Secondly, make sure you have a super clear understanding of your story. I get not everyone likes to plan everything ahead of time, but try and find one singular question which you can use for your story. For example, “Will character1 allow herself to love again after swearing all men off forever?” or “Will character1 fulfill her dying mother’s last wish?” etc. so that no matter what happens in the book, you always have a clear understanding of what is supposed to happen and don’t get too offtrack.
There’s 10000 more things I can say haha, but I’ll just finish with this. Make sure everything you write/code has a purpose. Once again this is for storytelling in general and goes back to that one question you have for your story. If a scene doesn’t add anything for the story and has no meaning, then why even write it? Your scenes need to matter in order for your story to move forward smoothly and keep your readers engaged.
Oh I almost forgot, write what you would want to read! Don’t chase after what you think other’s will want to read. Episode has a database of millions of weekly users, you will find people with the same taste as you.
I hope that helped, I have a lot more I can say in case you need more help! As for coding, just know that most people don’t need super advanced coding to like the story. Especially for your first one! Make sure to just spot direct, have smooth scenes, no errors, etc. If you want to experiment around then Joseph Evans!! But other than that, if you have an interesting and engaging plot, then you’re all set. <3