"When it comes to enter the initial password...."
Is that the password for the "admin" account that's used to log into the router? If so then are you entering the correct password? According to the user manual it should be on a sticker on the back of the unit. If that doesn't help then try a different web browser to connect to the router.
"my laptop is only letting me enter a max of 8 digits"
I'm not sure what that means - post a screenshot if you can to illustrate this issue. If you can't then it may help if you describe fully what's going on there.