Whether or not you should register a domain is of course a matter that only you can decide. All we can do is to offer good advice.
There are several different reasons for registering a domain.
The most common practice today is to register one or more domain names to protect your name on the Internet. The importance of registering your domain name cannot be overemphasised, even if the theft of domain names are no longer that common, there are many people, services and companies with similar names and ideas.
It is also common practice to register a domain name to create your own identity on the Internet.
Email is used extensively throughout the world and companies, organizations and private persons want to get email and web addresses that remain the same. There could be problems having an email address in the form of myname@ISPdomain.tld and the web address http://www.subdomainforcustomers.ISPdomain.tld/~companyname, which only last as long as you stay with the same provider. If you have your own domain you never have to change email and web addresses.
If you have your own service on the Internet it could be a good thing to let it have its own web address; www.yahoo.com, www.mumbaihosting.com, etc.
If you do business in more than one country it could be useful to reserve domain names in the countries in which you are represented and also in the international top-level domains .com, .net, .org, . firm, .shop, .web, and .info to name a few.