I'd have to say I first started doing voice over as a back yard wrestler. I would do commentary for my friends' shows. Later, after I got trained and became an actual pro wrestler, I gained more experience in the ring giving promos, as well as doing more commentary work and spending time on and off being a ring announcer. I worked as a DJ for about ten years with my father before I started working as an audio/video engineer for a university. Since I've been working at the school, I've read for about ten online courses ranging from computer classes to MBA classes.
Professional wrestling was really where I got my start. That and working as a DJ got me a lot of experience doing live voice work. Since 2013 I've gotten more experience reading for online classes.
The studio I work in primarily uses Heil PR 40s and and a Mackey sound mixer. We use Adobe Audition for our recording and editing.
I studied international studies/history/political science in college. As a result, I gave a lot of presentations. I became very good as sounding very knowledgeable even when I wasn't entirely confident. It also helped me to speak passionately about things I may not have cared about in order to better connect with my audience. My pro wrestling experiences helped make me better able to put myself into a role that may be nothing like me and speak as if I was that person.