Finding a decent girl is not a matter of five minutes. Statistics show that you have to chat with at least 20 girls on the Internet to find the one that really into you.
If you haven't started an affair with someone, it's okay, then it's just not your partner and you go further in search. If you did something wrong, analyze why you did not succeed and do not repeat these mistakes in the future.
Perhaps you took a long time to say important words or, on the contrary, were too harsh. The girl to whom you have become interesting will not leave you and stop communication.