How do I upload my posts?

[Admin]

Where do you currently have these posts? What kind of files do you have?

If you’re trying to migrate a full WordPress site, this is the best way to do it:

How to migrate your website to InfinityFree

If your website doesn’t use MySQL databases, moving your site is very easy. Simply upload all your files to the ‘htdocs’ folder on your hosting account with FTP or a file manager. If you have a PHP based website, check if it has any configuration files where a domain name or file path needs to be set. Update these values as required. If your website is using MySQL databases, you need to move the database contents as well and update the configuration of your website to use the database: Backup…

Or the same process described by WordPress:

Moving WordPress