changes to at wordpress site

On the page [login to view URL] I need some changes. The page is build in wordpress with a child theme. You get access to wp-admin. I expect this can be done without installing any plugins. I need the following: All pages need to use the same [login to view URL] template from the chield theme. The address [login to view URL] needs to lead to the page "SÅDAN KOM VI I GANG" All text in the menu including the mobile form and the "NÆSTE KONCERT:" banner needs to be white The menu background including the mobile form and the "NÆSTE KONCERT:" banner needs to be color #003559 The posts in the "Koncerter" page needs to be placed nicely under each other When the menu and banner color is blue there is a thin white stribe over and under the feautured image og each page. That needs to be removed.