How can someone code a website and give it a name like eg www.sololearn.com

Question

How to name a website

Answer 1

Yemi Onakoya
Those are called domain names and you need to buy them in order to use them.
And you need to host your website(files) from some servers which also costs money.

If you want to host your website for free(there are limits though) you can use GitHub Pages which is very good for hosting small websites that don't use lot of bandwidth.
Ex.
https://hanumaukkadapu.github.io/myCodeBits/color-picker-tool/