What not to say in a first message
'wanna chat', 'hi alexander1234', 'hello sexy' first messages with just those two words, nothing else.
With such kind of text messages you will not get a date with alexander1234, and no sex or hookup for sure!
You need to be gentle, you can start your message with nice words like 'hi beautiful', 'nice picture', 'you are hot'. But you have to say also something about yourself, your name, age, city. If you are in the neighborhood of Utrecht, you absolutely need to tell that to alexander1234.
Good luck with online texting and flirting !