You don’t get FTP login details for your website. We don’t think you need it. You need to be a trained developer to touch the code. One wrong line of PHP and your website goes down. You Can do anything and everything from the WordPress dashboard. We’re trained WordPress Developers and even we don’t do much coding these days. That being said if your keen to be able to do a bit more customisation wise then you could learn CSS and add custom CSS from the WordPress dashboard. You can also access all your themes files and plugin files from the WordPress dashboard including your theme’s functions.php file. However, we recommend you don’t touch it unless your 100% confident that you know what you’re doing or you’ve hired a developer who does.