You don't need a state-of-the-art production studio to work in voice-over. You do need good enough equipment to record, edit and submit a good audition. A computer with a microphone and a mixer may do the trick. It's important that the room you record in be as soundproof as possible – if you use a walk-in closet where the clothes muffle the sounds outside, the industry's not going to complain.
Be mindful of the sounds of your heating and cooling system (this goes for a home recording studio, as well). If you can’t find a spot where you can’t hear air rushing through your ducts, you may want to shut down your furnace or AC for the duration of your recording. If your recording space is near a window, listen for sounds of traffic — especially loud trucks. They will definitely show up in your recording.
You need to appreciate that there is a lot to learn and do before your first paid voice acting job. Yes, you want to get out there and start auditioning. But first, you’re going to need proper training, equipment, resources, and yes, some natural talent. The great news is that even though the voice over industry is competitive, there is plenty of voice over work out there for everyone. This guide on how to become a voice actor will give you a good idea of where to start.
As editor, you need to turn the raw recording into the final version of the file you'll be sending to your client. Editing during a recording session can be problematic, and particularly so if you're recording in a domestic environment. How can you expect to hear the drone of the dishwasher ruining your recording if the dishwasher is still running as you edit? I'll look in more detail at setting up a voiceover recording studio next time, but for now, if recording in a separate room or isolated booth isn't an option, at least try to edit the file the following morning (or maybe at night) when there's less noise around — because hearing your recording with a fresh ear and in a quieter environment will help you to make better editing decisions, and will reveal noises that slipped your attention earlier.