This is important. You will need to choose a theme that suits you. Log on to the web and starts surfing. Check out the design of the sites you see. Make a list of all the pro and cons of others’ website design. If you see something you don’t like, make sure you don’t make the same mistake in your website design.
Do you want your site to be very formal or informal? This depends of the type of business or theme of your site. If you are promoting professional profession then the content and design should be formal. Being formal doesn’t mean that you site have to be boring?
Check out what is the technology that a site is built on, if you like it very much. A site that is easy to navigate will attract more visitors and the chances of repeat visitors will be high. If you find all these too hard for you, try contacting a web design professional for help.