Your form looks nice, but there are a few issues with usability and accessibility.
I think the blue colour is nice, I like it a lot, but it doesn’t offer enough contrast to the white text if you want this to be accessible to every user.
You can check that here: https://webaim.org/resources/contrastchecker/
If you want to keep the colour, you need a different, darker background for the text.
I would change the box size for Age. That number doesn’t take up the same space as name and email address and we humans notice that as something odd. It takes our focus away from the form for a second and it’s best to avoid that. Don’t make your users think. There is an interesting book about that: https://en.wikipedia.org/wiki/Don’t_Make_Me_Think
I would also make the text box a bit larger. Even if it’s possible to enlarge it, most people will never use that, because they don’t know it’s possible. So make it the size of a short text. A little longer and wider than it is now. That way there is more chance users will actually leave a message for you.
I like the way your text is alined to the right. It makes it so much easier to read. Just use that for the submit button as well or place that button in the centre of the form, or in the centre of the left part of the form. And of course that button needs a different colour that makes it stand out and with an accessible contrast as others mentioned.
I would use a different colour for the *. The orange is hard to read against the blue background-colour. Maybe that’ll improve with a darker background, but if not, choose a different colour or different shade of orange.
But like I said, I think it’s a nice form, I like forms like that with white text on blue. I’ve tried different colours on my own forms, but for me the blue background helps me to make a form easier to use. I don’t know why.
And a bit more on forms to help with structuring and readability:
Good luck with the challenges!