. . . I understand that you are a total novice, in terms of actual real-life D/s play. I applaud you for taking the courageous first step towards fulfilling your innermost desires!
Now a few important points for you to consider. Firstly, with whomever you begin training with, remember to leave your expectations at the door. No doubt, you have been fantasizing about this for a long time. An entire universe may have been constructed in your head. In my past experiences with total novices, it sometimes seems that these prefabricated notions can actually become obstacles to surrending oneself in the here and now. So something to keep in mind as you prepare to meet the Mistress.
You mentioned attending a few munches, but I take it you have not played with anyone you met there? So you have decided to begin your training with a professional dominatrix rather than attempt a "lifestyle" relationship. Since you have no experience in either, I would expect you may have some confusion as to the differences. There are many, and they can be subtle. Some within the lifestyle community, a fair number of whom seem reflexively dismissive of pro dommes, would say that the difference is that those who do this for a living are "pretenders."
Of course, I see it in a more complex light. For one, I enjoy the well-defined boundaries of a session-based dynamic. And while I do consider myself a genuine dominant, my bandwidth is such that my training of new submissives is limited to session time. Remote sessions or other forms of training may also be possible, within my time constraints and with appropriate tribute. I note this in regards to your desire to have assignments and duties between meetings.
If this all sounds suitable to your submissive aspirations, feel free to follow up with me. . .