The security part will be handled by a very good, complex, and safe plugin, called iThemes Security. It will be installed and configured when your website will be set up, or when you subscribe for the maintenance and support plan.
Depending on your web host, a free SSL certificate from ‘Let’s Encrypt’ can be installed, which will basically allow your website to use encryption, by using the HTTPS version, instead of HTTP. If the ‘Let’s Encrypt’ SSL certificate will not be available on your host, you can purchase another SSL certificate.
With those two main features in place, you shouldn’t have any problems against bulk or even targeted attacks. Of course, no website can be 100% safe, but unless you upset Anonymous or some other major league hackers, you shouldn’t have problems :D.