Registering multiple domain names has many advantages.
When starting your business, you should always look to the future and consider opportunities for growth. If you plan to expand your business, which is now limited to one specific product or service, to other products and services in the same category later, then it is best to register other suitable domain names first. Because competitors who notice that your business is becoming successful could otherwise register them for you!
Also consider registering variations of your domain name. In addition to the .hr domain name, be sure to register the .com and .net variants, for example. In this way, you will have an advantage over domain squatters who would register a domain of your name and then ask you for a large amount of money to resell it to you.
But also consider typosquatters, i.e. people who register a domain name with typosquatters in the name, thus luring Internet users to their website when they actually wanted to visit yours.