Plugin Issues with installation / updates / deletion

Hope someone can provide a little guidance on this, as I’m having a fair bit of trouble with Plugins at the moment.

I currently can’t install, delete or update plugins, and get a variety of error messages.

For example, the error I receive for updating existing plugins is:
An error occurred while updating WordPress SEO: Could not remove the old plugin.

When deleting redundant plugins there’s:
Plugin could not be deleted due to an error: Could not fully remove the plugin(s) wp-sitemap-page/wp-sitemap-page.php.

When adding new ones its:
Could not create directory. /var/www/booxweb/html/wp-content/plugins/pluscaptcha/

Could this be a permission issue with my hosting provider??

Any help you can provide would be appreciated!

Thanks