I Made WordPress Multisite. And Now Everything Doesn’t Display Properly

I don’t have experience with bitnami so I don’t know how it changes the apache configuration but I would say the problem is the domain mapping.

mywebsite.com maps to lets say /var/www/mywebsite
but your wordpress is installed in /var/www/mywebsite/wordpress
so the url to it isn’t mywebsite.com but mywebsite.com/wordpress and when you login it redirects you to mywebsite.com/wp-login beacuse in the dashboard you set the site address as mywebsite.com and not mywebsite.com/wordpress.

I would say you have two options:

You can change the site address that you entered in dashboard throuhg mysql in table wp-options, the siteurl value (you can do that thorugh phpMyAdmin if it is installed on the machine)

or

Change the document root for mywebiste.com in you Virtual host to the directory where wordpress is installed (you just add /wordpress to the end) (VirtualHost examples if you’re begginer with them)