I have this small question and hope I can have some help,
what is the best way to prevent spammers from creating accounts on my website? is there any plugins useful for that?
"I am using WordPress for my website"
It's been long since I've used WordPress. I believe a Captcha will solve the problem you have. I found with a simple google search this plugin which will add Captcha Code on your registration form. This will provide an extra curtain of security against spam robots.
If the users that are registrating on your site, are real users (humans), then the only solution I can think of, is to close the registration form for a lengthy amount of time until they are bored with spamming your site.