Bloke

Where did you get that code for the form? This will not work inside the WordPress/Widget set up like you have.

The admin login should be url/where you installed WP/wp-login.php

I don’t know if you are putting this directly in a post or page. Or are you putting it in a function? You can try this:

$upload_dir = wp_upload_dir();
echo '<img src="'. $upload_dir['basedir'] . '/images/xyz.gif" />';

or this:
 echo '<img src="'. site_url() . '/wp-content/uploads/images/xyz.gif" />';

Just trying to help. There was a reason I was asking what your “site” URL was not your URL. Your WP site URL. You said emilniemi.com/a So do you log in at emilniemi.com/a or emilniemi.com

If you are not on a dedicated server then that is not the problem. If you do have control over it you should be able to reset it.

Look at your wp-config file and check the database credentials are correct.

What are the error messages you are getting?