I will help to state the full model number of your TV
The default password is usually 0000
You should go into your TV parental/security settings and remove this.
I can only get onto the default webpage on my tv. If I try other pages it tells me the site is not on my approved site list. When I try to go onto approved sites icon on the settings page it asks for a 4 figure passcode. As far as I know, ( having only had the set 2 days) I have not setup a password. How can I rectify this please?