Disable HTTPS on Google Compute Engine

bitnami developer here.

I've created an instance of wordpress on Google Cloud Computing and by default my blog is not serving https.

Anyway, if you want to disable the HTTPS on your blog you should go to the opt/bitnami/apache2/conf/bitnami/bitnami.conf file and look for some rewriting configuration like this:

<VirtualHost _default_:443>
  ...
  RewriteEngine On
  RewriteCond %{HTTPS} on
  RewriteRule (.*) http://%{HTTP_HOST}%{REQUEST_URI}
  ...
</VirtualHost>

And delete the rewrite condition which is making change the url from HTTP to HTTPS.

Regarding your second question, here is the official guide on google cloud computing about giving a hostname to your instance. https://cloud.google.com/compute/docs/configure-instance-ip-addresses

Also, apart of doing that you should change your wordpress domain in order to fix the permalinks of your application. https://docs.bitnami.com/google/apps/wordpress/#how-to-change-the-wordpress-domain-name

Hope this is useful for you.