First, welcome to the forum- when you get a minute, stop over by the intro section, and say hello.
So- you want to become a manufacturer of NFA firearms? Well, to start with, I would not use any of the "kits" to obtain your license. But I would spend some time reading on the ATF website. Here is a start- ATF Online - Firearms - How To - Become An FFL
Can you do this at home? Depends. Can you legally operate a business in your home? ATF requires you be in compliance with all state and local laws before granting the license. That includes ZONING. My local smith DOES have his shop in his home. YOUR zoning laws may be different. Got a business license?
Secondly, you MUST intend to "engage in the business" of making and selling firearms. The license will NOT be granted for "personal use".
Last, if you intend to manufacture full autos, you have additional measures to deal with- your ONLY customers will be Law Enforcement AGENCIES, military AGENCIES, or other dealers. No newly made full autos can be transferred to a private citizen. SBRs, SBSs, and suppressors are another matter.
And you did not ask, but if I were going to set up a business, I would incorporate it. It shields your personal assets from legal actions (like lawsuits).