The first thing you need to do is take a deep breath. It's okay to feel anxious, but really there is nothing to be anxious about. Middle school fundraising is nothing more than parents, staff, and kids working together to help raise money for their school. The only thing you have to worry about, of course, is choosing a middle school fundraising activity that will go well with your group, and that will help you meet your financial goals as well.
Middle school fundraising comes down to considering the number of people in your group, thinking about their target customer base, and choosing a fundraising activity based on those factors. Small groups especially need to choose carefully, because you don't want to be caught out with a middle school fundraising project that ends up being eaten away by high minimum orders or shipping charges that cut into your profits. Things like middle school scratch cards will keep profits high, and they are popular across the board. If the kids will be selling to their fellow students for their middle school fundraising, perhaps you could consider one of the classic candy bar fundraisers, which are great fun and very lucrative.