Migrating wordpress site from one host to another is hard for novice user. There are lots of plugins available for wordpress migration. But you need to have some technical knowledge to use these plugin. If your site is very big in size, specially the database, then these usual plugins will not work.
But i found one plugin named “Migrate guru” which is able to migrate large website from one host to another. No matter how big your website is.
Recently i used this plugin to migrate a 13 gb website. The migration was successful but it took few days to complete.