As a freelancer/self-employed professional in the Netherlands you can take out insurance for many types of risks. Most insurances are voluntary. There are, however 2 types of insurance that you are obliged to have.
National insurance schemes
National insurance schemes (social security) are compulsory for everyone working or living in the Netherlands. Freelancers/self-employed professionals in the Netherlands pay national insurance contributions through their income tax.
Mandatory healthcare insurance
Everyone living or working in the Netherlands is legally obliged to take out standard healthcare insurance. Thus this also applies to the self-employed. You can choose if and which additional health insurance you wish to take out.
Other types of insurance are voluntary. You should consider the risks you are willing to take. If you do not have insurance you may have no income if, for instance, you fall ill, you have to terminate your business, or during the period around childbirth.
Business insurances cover risks that you run as a result of having a company. You do not have to take out insurance against these risks. However, if you have a car or property in the name of your business, or if you have a specific profession, you need insurance for it.