great question and perfect timing to answer me!
So, basically there are two types of domain sub-domain and domain. Thy both can get free! www.dot.tk and many other but truly speaking they are of no use. I started my website few days before with a free domain and hosting account from Heliohost. My domain got canceled and the hosting account is very slow with no uptime guarantees.
Second if you are going to start a website and run it properly with contents it may take months and may be years to visible in search engines because many of the free domain are blacklisted by google and other search engines.
In my opinion and experience, truly speaking go and be with proven blogging platforms. I also failed to start my free website and at lats went for hubpages and blogger (blogspot.com) or wordpress.
If you started with blogger definitely you will be getting lots of trafic from google itself and if you succeed with your niche upgrade it with a premium hosting and with a top level domain.
In a nut shell do not run for free domains and hosting packages if you want to build your emire with it. Hubpages, blogger, wordpress.com, and other web 2.0 properties will be the best. Suggesting you for Hubpages because it already recieves millions of traffic.
Thank you. If any questions or still in doubt fell free to ask me its always welcome!