website

Yes, why not?

You can do that. It was the first thing I did after starting my business.

You can do it yourself or you can outsource it. What is essential is that you apply for a domain name (via your hosting provider or directly at www.domein.be) and sign a hosting contract with a hosting provider. Many of these hosting providers offer a choice between a basic package with a simple website builder app (where you don't need to know anything about HTML, CSS or scripting and can simply upload text and photos) or more comprehensive packages where you can do everything yourself or build your website using more advanced systems (such as WordPress, Joomla, Drupal, etc.).

All costs you incur (domain registration subscription, hosting costs, web design costs, text editor costs, internet subscription costs, having photos and video made) are professional expenses and can be claimed if you have invoices for them (or proof of purchase if you buy from a private person). You may only be able to claim part of your internet subscription as a business expense because you also use it for private purposes.