The easiest way to create good looking content for your profile or some of the other fields in the system is to use a 'WYSIWYG' editor.
One such editor can be found here: https://html5-editor.net/
A fancier option that shows HTML, CSS, and JS side-by-side is https://codepen.io/pen/
This editor is especially handy because as you enter your content in the right hand panel, it generates the appropriate HTML in the left hand panel.
There is also a cleaner, which is helpful if you paste content over from another program:
Click clean if you pasted something into the right hand box and it has its own format that you want to get rid of.
HTML Tags Cheatsheet
As a basic primer for HTML, you really, really should take the time to learn the basics. Using the editor we show above, you don't really need to. Just enter your content into the editor on the right and copy the code on the left to paste into a basic text box such as the 'About' section of your agent profile.
Headings and paragraphs are your friend. They'll arrange themselves automatically and will make your text look good.
If you plan to use images, first figure out where you are going to host them. When you host an image, it lives on a server somewhere and you can access it with a URL.You can upload and use your Google Drive account. Other image hosts can be found with a quick google search such as https://imggmi.com/.
This extensive cheat sheet will give you all of the various tags and attributes you can copy and paste into any text fields or </> code boxes.