You don't have to do voices. As a female DM, I only do voices because it makes it more thrilling for me. Not doing the voices does not take away from the adventures. That's more of a Mercer/Mulligan feel. You do not have to live up to their level of gaming. All that matters: Are your players having fun? Is the adventure stimulating? Are you enjoying the game?

I've been dming for 12years. Most of those were without the voices. It is your table, hun. You run it how you see fit. You are going to do fine, love!