こんにちは！
こんにちは。よろしくお願いします。

Hello, Alex!
Here is Alex! Nice to meet you!
Why don't you try a self-introduction? Try to say things like your name, where you are from, etc. You can search for the key expression 自己紹介（じこしょうかい） and try something longer.

Good luck with your Japanese studies!

Alex.