https://haveibeenpwned.com

google chrome also has a feature that checks the passwords you enter against ones in known data breaches.

on top of changing your email password (or any other site that uses that password)...you should enable 2 step/factor authorization whenever possible.

also NEVER use a debit card for purchases. that gives thieves a direct line right into your bank account and theres no protection of your money (your bank will prolly make *you* pay it back if you have a negative balance). use a credit card whenever possible (0 fraud liability and chargebacks).

if you cant get a credit card and need something for online purchases...sign up for http://www.privacy.com. you can create virtual cards for each site/purpose you need them. the charges do pull from your bank account but you at least have the option to pause cards, close cards, set spending limits that block anything over the maximum, etc.