I think you need to understand the fundamental first.
1) Please link to website where is possible created for free my own cryptocurrency.
You can do some google search yourself. Plenty of resources out there. If you want a simple one, you can try to create token on Ethereum blockchain, which is considered as currently the simplest and easiest way to create a cryptocurrency which is safe and secure.
2)If I registrated cryptocurrency name...nobody registered the same ?
The name of cryptocurrency is decided by the public. Which mean if majority of people name this currency as "ABC", and all major exchanges or listing website follow the name, then it is named as "ABC". Anyone can still call it "DEF", but other will not understand it because they recognize it as "ABC". If someone use the name "ABC" as well, it will be up to the public to decide which "ABC" is the "ABC" they think it is.
3)Please link to website where is possible sale my own cryptocurrency.
Right now the easiest way for other to trade cryptocurrency is through online exchange, for example Bittrex, Binance, Bitfinex and many other. You can still create your own website and sell them yourself, or let people trade with each other in a person-to-person manner. It is up to you or the public for the way to trade your cryptocurrency.
I suggest you to understand the basic of blockchain technology first.
