Dashboard does not apear /wp-admin

Hello guys,

I am new with wordpress so please forgive me. Also my English are not the best.

A friend of mine created for me a website using WordPress.
Now I bought a new domain name under the same host to create another website (actually a forum). Since my friend has zero time for me now due to family and work I decided to proceed alone to set up a simple forum.

When I go the control panel of my host server I can see that wordpress is already install for my new domain. I dont know how.

The problem is when I write on the address bar http://www.myNewdomainname.com/wp-admin a website appear with the title at the top Index of /wp-admin/ and there are a lot of files to explore (like the folders on the computers with the name css or images or netowork) instead of the option to log-in and proceed to the Dashboard.

How can I fix this?

If you think this is complicated for me please advise not to proceed. I have some basic knowledge.