Online reservation form design help [closed]

I am currently building a little nodejs reservation tool. It behaves as it should but looks very crappy, crowded and overwhelming. Since I have no experience in designing, I read through a lot of online tutorials and stumbled across material design, which I then tried to implement. Well, it sucks (because of me).

You can view a 'live-view' here.

The layout is only build for mobile phones thus far but before I continue to expand it to larger resolutions I need to rework it completely.

Any ideas, layout choices etc. pp. you would like to introduce me to? How can I fix this?

I am aiming for a clean, modern, youth appealing design.

Thank you very much!