A company website is now the norm — customers search for services and products in Google; without a site you’re harder to find and to trust. Even a simple business card with address, opening hours and a contact form gives a reference point and makes the first contact easier.
Depending on your industry, useful elements include: description of your offer, portfolio, testimonials, blog (for SEO and authority). A larger site makes sense when you have something to show and want visitors to stay and learn more.
If you don’t have a site yet, start with the basics: who you are, what you offer, how to get in touch. You can then add pages and content step by step.