I notice that compared to other professional sites, the text on my site look kinda weird, its hard to explain what i'm saying but its like it looks all messy or something.

1. What is the prefered font size most websites use??
2. What color font would be best for my site??
3. Any ideas or suggestions on how to make the text on my site look more professional, organized, etc.. would be greatly appreciated.
4. What font would be better for my site

Thank you, and i'm sorry i asked so many questions in one post lol.