i am having problem with my network i cant access anything

I can access my main site dashboard. what I mean by dashboard is the content of the actual dashboard content functions. I tried to add another site on my network and the new site is copying all other fuction of another site with all the products and pluggings . and everytime I tried to go to another site it keep asking me for my password and wont let me go into the site I am inquire. also my registration page is not loading. I am so frustrated and don't know what else to do. pls advise.