I AM GOING TO ANSWER YOUR QUESTIONS IN ALL CAPS, I AM NOT "YELLING" JUST MAKING IT SO YOU CAN SEE THE ANSWERS BETTER!
Is a business license typically required? THIS WOULD DEPEND ON YOUR STATE LAWS. SOME SHOWS WILL REQUIRE YOU TO FILL OUT A TAX SHEET AT THE SHOW AND PAY TAXES TO THEM. THIS IS FOR SMALL TIME SELLERS WHO ONLY DO LIKE 3 SHOWS A YEAR!
Do you insure your inventory? MOST INSURANCE COMPANIES WILL "NOT" INSURE YOUR ITEMS UNLESS YOU BUY A RIDER! EVEN AS A COMPANY WITH A $100k INVENTORY IN MY HOUSE MY INSURANCE WILL NOT INSURE IT!
Details on how to do that? ASK YOUR INSURANCE PERSON!
If my designs are originals, do I need to protect my ideas? How do I do that without copyrighting, or is copyrighting a necessary step? IF THEY ARE TRULY ORIGINAL AND NOT MODIFIED FROM A PATTERN YOU BOUGHT YOU SHOULD COPYRIGHT THEM. BUT THAT IS REALLY ONLY GOOD IF YOU ARE GOING TO PRINT AND SELL THE PATTERNS TO MAKE THEM! IF NOT, THEN DO NOT WORRY ABOUT THE COPYRIGHT, IF SOMEONE BUYS YOUR TOTE BAG AND USES IT AS A PATTERN TO MAKE THEIR OWN, THERE IS NOT MUCH YOU CAN DO ABOUT THAT!
IF IT IS A GADGET THAT IN UNIQUE AND TRULY YOUR OWN DESIGN/INVENTION THEN YOU SHOULD SEEK A PATENT FOR IT!