Took the weekend course already thx for suggesting
Perfect! That course can save lives!!!
That said, read what everyone else posted. For me, bottom line is to wear everything from head to toe.
I've been riding for 30 years, mostly cruisers, and I used to never wear any type of armor. I'd have a helmet but most of the time it was my half helmet.
Eventually, I wrecked with only jeans, rain jacket and half helmet. Slowing down and bit it at maybe 30 mph. Rolled about 8 times (from what I remember as it happened in slow motion...yet so quickly!). I think the one major thing that saved me from going down is my training as a bicycle cop and the MSF course - if you're rolling...then just go with it! And I did and tried to be as relaxed as possible. Had I tensed up I think I would have had a lot more road rash.
Wound up with a knee that swelled to the size of a grapefruit but, luckily, no broken bones! And some minor road rash on my elbow.
SINCE THEN...I ALWAYS wear an armored jacket, 3/4 or full face helmet (I live in Florida and it get's sweltering hot) armored gloves and, when riding to work, armored pants. I also normally wear some kind of boot, non-armored, but it's better than Harley flip-flops!!!
I will add...whatever you chose does NOT have to break your bank account! I'll argue with anyone that you get what you pay for because I have some cheap(er) gear that's rock-solid! And then I have some more expensive gear that sits in the closet.
To answer your original question:
Minimal - helmet, gloves and jacket
Non-negotiable - helmetl
Extra - armored pants and boots
All that said...hit up Cycle Gear and your local shops. Try on as many brands and styles as you can because they ALL fit differently! When you find what FEELS COMFORTABLE and fits your price range get it. Chances are you'll be getting more gear as time goes on and technologies improve. (Plus wear and tear)
I prefer comfort first and foremost as I can always "armor up". Next I weigh price because why pay top dollar for something that will get sweaty/dry/faded/etc over a year or two. Style is last on my list. I'll try to get a match color to my bike but, more than anything, I want to be seen and maybe ugly as opposed to invisible but cool.
Have fun shopping, try things on and then write up what gear you like and don't so us knuckleheads have an idea for our next shopping excursion!