So you found a domain name in aftermarket places like GoDaddy, Sedo or, well, here? That is not a guarantee for its quality. Mind these steps when buying an aftermarket domain name.
1. Do your research
What did the previous owner use the domain for? Did you just buy your family business a domain name used for porn?
2. Is the username free in social media?
It could be the most awesome domain name, but is it taken in social media like Instagram or Twitter? Just because you own the .com you do not automatically get the username.
3. Is it a fair price?
Buying a domain name is like buying real estate. Its price depends on numerous things like extension (com, org or what ever), length, keywords, age, meaning, personal meaning etc.