We don’t usually recommend it.
The free domain name that comes with your hosting plan is tied into your hosting plans billing. With some hosts, the domain name actually identifies your account.
The problem with this close tie between domain name and hosting is that it makes it more difficult to move your hosting later, which most people do eventually.
Another problem is that sometimes (not always, but sometimes) the Free Domain Name is only free the first year, and you have to pay for it after that. Usually, in this case, the renewal fee is several dollars more than it would be from a low-cost domain registrar.
It is much easier, and usually cheaper in the long run, to host your domain name with a decent, low-cost domain name registrar, and use the free domain just as a placeholder or identifier.
