At some point it may/should ask you to go to your Google account on the WEB and change your password for your account. Then if your tablet is WiFi connected even though it's locked, it should let you in. The only other option if that fails is a factory reset but it should work.
Well, an awful lot happened here in ½ hour. Seems all that's left for me to say is, "Welcome to the forum, Cerdan. Nice to have you as a member of Android Tablets."