Hi Lainy
Welcome to the Community! Iceland is wonderful - you'll love it.
I went on the JY tour three years ago and thoroughly enjoyed it. The food is amazing. If you put 'Iceland' into the 'Search' function at on the top right of the page, you'll find loads of reviews and tips from JYers like me, but if you've got any other questions having read those, happy to help.
Top tips - pack lots of layers that are easy to take on and off because you'll be in and out quite a bit. Also, some sturdy walking shoes or trainers with really good grips or some removable ice gips like YakTrax (that you can get on Amazon) because it can be quite slippy underfoot. Be aware that it is a quite pricy country, but forewarned is forearmed, and don't forget to keep all of your receipts because you can claim back all the tax at the airport on the way home.
Have a super time
Mandy