It depends on what you want to do on the site. If it,s a blog, you can use blogger which is free www.blogger.com . I assume you do not have prior skills so i'll list other platforms that are pretty easy to use. You can use joomla, wordpress, or download web page maker if you want to make static sites. You will also need a domain name eg www.sitename.com and hosting, this will cost you some money. You can then place ads on your site to make profit, if that's what you want.
If you need professional websites, you can contract it out to website designer and developer. If interested, you can send a mail to firstname.lastname@example.org and i'll build if for you at a reasonable cost and time frame.