I'm glad you're getting more polite responses than I did. I had people telling me I was ridiculous for wanting a celebration for our 10th and to get over it. And as someone else said, I also got PMs calling me names.
Start by talking to your pastor and seeing how much it would cost to do the ceremony there. Some churches allow you to do it for free, others will charge you a fee. I would spend the majority of the money on the party/reception. Decide where you're going to have it, then decide what kind of food you want. Once you've decided what kind of food you want, then you can decide if you're going to "cater" yourself, or if you're going to hire someone to do it.
For a vow renewal you can send out e-vites. If you want to decorate, you can find flowers for cheap, or just do candles everywhere...or a combination of both.
If you have any questions, feel free to message me. Our vow renewal is in 5 1/2 weeks. I've done all of our planning.
*hugs*