After six years it's finally time to upgrade to a DSLR from my handy and very useful iPhone/lapel mic combo. I have never combined audio and video on software so this is all new to me and the more I read the more lost I become. Technology an A/V is far from my strong point here!
I have a snowball mic with pop filter and a Cannon EOS 6d already. The latter I am still learning. What is the best software to use to combine audio and video? I have been using a Macbook for editing with Final Cut Pro X and iMovie. My videos are talking head videos, with little editing beyond the title, but hoping to add some graphics moving forward like this:

Can anyone point me in the right direction on software to do this, specifically easy to use program, or can I do this on FCPX or iMovie? I would love to not have to pay for one more thing after I just built a studio in my home.