I am going to host my own website, using Microsoft's ISS to host them. My question is that when I am hosting them, and I want to update them with a newer look, will I just be able to edit my HTML code and then the next time the page loads it will show the new content?

You'll need to upload your new webpage again, or use such CMS tools like WordPress.

Always have a production site and a test site. Do all changes to the test site and then when you are happy, copy the entire thing over to production. If you are using something like asp.net, don't copy the web.config as that will typically have settings specific to that environment (database connection strings for example). If you are connecting to a database, you shoud have production and test versions of that as well.

Hi,
we can change and update any webpage using Hosting account, with the help of File Manager.
here i write the steps to How to webpage content? through file manager

1.Login to your Control Panel
2.choose File Manager from the category "Files"
3.Double click the public_html folder icon in the center section of the screen.
4.Select the file for the the 'page' you want to edit. Usually the homepage or default page is index.htm or index.html.
5.After you select the file, you can right click on the file and choose "edit" or "code edit", or you can use the icons along the top of the screen to edit the file.
6.The file should open in a new tab or window in your browser.
7. Once done making your changes, Click the Save button, located in the top right hand side of the window.
It may be necessary to click "reload" or "refresh" on your browser to see the new version.

-Mike

Keep us updated on your work, we'll check it out.