Hello Edwin,

You can use http://www.dot.tk/ or http://www.dominio.gq/ if you are educating yourself, however I would not use this for say a public facing business as these free domains generally have a bad reputation as they are abused by spammers and these free services are never reliable.

For a cheap domain name I recommend https://www.ionos.com/ you can get a domain for under $10.00 a year. They claim $1.00 for the year but they price always goes up by the time you finish configuring and checking out.