If you are using the web-building tools provided by your webhost (this usually means that all of the HTML files e.t.c. are located on the webhost and are accessed via your web-browser or viaspecial editing software provided by the webhost). This means that you would not be able to use FTP because you must use you webbrowser or the special software.
However, if you are using software located on your computer then you can upload HTML and other files to your webhost using FTP (This means you are not using the webhost's special web-building tools). This is often a bit harder for computer beginners as the webhost web-building tools tend to be designed to be super easy to use so that anyone can build a website.
However, you can choose to work from your own computer and build the website by using a HTML editor or WYSIWYG web editor ('what you see is what you get' web editor). Then you can upload the changed HTML files very quickly and easily using FTP software. For FTP software you can use stand-alone software or sometimes HTML or WYSIWYG editors come with their own FTP utility pre-installed.
So if you take this option like you said you can use a HTML editor. This required creating webpages by typing (or coding/programming) the HTML code and saving the HTML files with the .html extention. This is more difficult for computer beginners but can be achieved. And there are some great resources for learning for example 'w3schools.com'.
Or you can use a WYSIWYG editor. These come in a vast variety of difficulty. Some are very difficult and require an in depth knowledge of HTML and CSS to use effectively. I would put editors such as Dreamweaver and Kompozer in this category. This will be too difficult as they are designed for experts.
However there are WYSIWYG editors that are much more automated and easy to use. One I know of is Web Easy -- but there are many more available. These are very like the web-building tools that are provided by some webhosts and they often allow you to create and link web-pages from scratch by using easy to use templates and step-by-step wizards etc. So I think that finding a WYSIWYG editor may be your best option. And if it has a build-in FTP utility/tool then that is even better.
Or you could go the route of learning to code directly in HTML (which at some point you will need to learn to some extent regardless). In this case you can use a simple text editor (I recommend using something like Notepad++ which can be downloaded for free) Or you can just use the Wordpad or Notepad that comes with your operating system. If you decide to go this route you will definitely need to download FTP software so that you can upload the HTML and other files to your web-space. There are some good FTP software out there.. I use one called 'FTP Commander' and also 'FileZilla' but there are other free ones available (and maybe better than these). Especially if you spend money you may be able to find better quality software. I hope this helps to point you in the right direction and good luck!