If you want to move your blog from Blogger to Wordpress, you can get some things done before switching your domain dns records to the WordPress site.
Create a hosting account linked to your existing Blogger custom domain name but do NOT make changes to your domain name settings. Do not change nameservers.
Log in to your cPanel and install WordPress. After insallation, you will not be able to access the WordPress site though because your domain name settings are currently not pointing to the WordPress site. So, you need to follow the steps below so you can access the WordPress site on a temporary url.
Go to the cPanel and create a subdomain eg wp.yourdomain.com and link it to public_html
Go to your domain name dns and create a new A record and point this to your server’s IP address. You can find the correct IP address in in your cPanel via Expand stats > Server Information. It might also be included in the welcome guide you received from your web hosting company after activation. So, if your subdomain is wp.yourdomain.com, let the A record be “wp” and point it to the server IP address.
Chill for like 30 minutes for the record to propagate. Once it propagates, you should be able to access your WordPress site via http://wp.yourdomain.com but it will not work properly. So, next step is important.
Go back to cPanel and navigate to phpMyAdmin. Click on the WordPress database table, click on “Options” and replace the url in “siteurl” and “home” with the subdomain you created >> wp.yourdomain.com. Save all changes.
Now, you should be able to access, log in and work on your WordPress site via wp.yourdomain.com
When you are done with setting up your WordPress site and ready to switch your Blogger blog to WordPress, you can go back to PhpMyAdmin to update the tables and switch your domain dns to the WordPress site.
I hope this helps.