There's no reason to defer the effective date.
The best date would be when you are in the process of setting up your business.
Once you have the business established, you'll have more options as to how you treat your expenditures.
If you are the sole owner (member) of the LLC, you will be able to simply file a Schedule C with your personal tax return to report your business activity.
Sorry, I did have another question, If I have been purchasing tools and supplies just prior to (like a month) the effective date and I utilize those tools and supplies for the new business, can I effectively count those expenses towards the business?