Any website built on a CMS (content management system) like WordPress, Joomla, Drupal, or Magento (among others) do have dashboards where you can login and add, edit, or delete content yourself. You'll see what kind of resembles a document editor like if you're using Microsoft Word (some websites use a block-based system of editing).
With this interface, you'll be able to:
We do provide training for our clients - just contact us and schedule that online training.
If you want to manage more than just content, please let us know so we can discuss that while building your website as there may be some areas where you would otherwise need to know some PHP code in order to make changes. All normal areas of the website you will be able to edit yourself, no problem.