re: Should I rent or buy equipment for my first backpacking/camping trip?

You won't be laughed at, but you will be uncomfortable the whole time. There are plenty of backpacks out there for under $100 that are great starters. The one I use was only about $60, and I love it. It weighs a bit more than more expensive options but mine has adjustable straps and waist pad which is great since I am 6'4". I have cut off a lot of strap etc on it that I didn't use to cut weight. Now my base pack weight is about 15 lbs.