Should i be using Flexbox in my project?

Here is a site that does a great job explaining flexbox. During the courses you are just being shown different layout skills. It is up to you which you would like to use. Flexbox would make a responsive navbar easier to create and maintain but, there is nothing wrong with using inline-block, block or something else.

The flexbox properties can be used however you like and can be combined as well.

https://css-tricks.com/snippets/css/a-guide-to-flexbox/

Thanks for your answer and the page is very usefull.

I still cannot seem to make a nav convert from column to row though. my html is set out like this:

<header id="home"> <h1>David McEnnerney</h1>

    <nav class="main_nav">
        <ul>
            <li><a href="#home">HOME</a></li>
            <li><a href="#portfolio">PORTFOLIO</a></li>
            <li><a href="#contact">CONTACT</a></li>
        </ul>
    </nav>

</header>

and initially set the css out like this:

header, .main_nav { display: flex; flex-direction: column; text-align: center; }

but in my media query when i want to set the nav elements to row they stay stacked as if in column?

@media (min-width: 769px) {

.main_nav { flex-direction: row; } }

Cant figure out why this is happening?