To find your company's public website, enter the company name into any online search engine (such as Google, Bing, etc.)
Some companies will have a commercial website and a corporate website. Others only have one or the other.
The commercial website is often the easiest to find. Commercial websites exist to sell products or services to customers.
Look for pages like "About Us" "Company Information" and "Investor Information" to find information that would be the most useful for an environmental scan.
Sometimes information aimed at customers can be useful for an environmental scan, but corporate information is usually better.
The corporate website can sometimes be found in a search engine. Most often, you will be able to find a corporate "part" of the commercial website by looking for pages like "About Us" "Company Information" and "Investor Information."