You want to keep reminding your audience of your brand and logo so that in the event they want something that you provide, they will have your companies branding in mind for when they require something.
Having a simple to use navigation system will help when it comes to keeping customers on your site as if they can move about the site with ease, they aren't going to get annoyed and leave so suddenly. Visitors to your site should be able to flick through your site's pages with ease and find specific pages within seconds. Don’t complicate something that doesn’t need to be.
Colour is key when it comes to catching the attention of your audience. Make sure that it matches your branding and is constant throughout the overall website. This will give it a professional feel and keep it look neat and tidy rather than a rainbow coloured mess.
When it comes to font sizes and styles, it’s a good idea to keep the fancier ones another look over. You don't want to use a font style that makes it hard for your audience to read, they may get annoyed and leave your site, therefore, increasing your bounce rate.
By all means, change the font style up a bit but keep it constant and choose something that everyone will be able to read.
Designing a website's layout takes time and trial and error so don't expect it to be perfect when it is first put together. Worst case scenario, you can always go back and edit anything that you don't find to be right, as many times as you see fit.