The meal plan at DL is only available if you purchase a package including a stay at a resort hotel or a good neighbor hotel.
There are many differing opinions on the meal plans, but it all boils down to: if you're not very careful, you can end up losing money because you don't spend them all. If you are willing to do a little extra work to keep track, they can be a somewhat good deal. The larger the meal package you buy, the larger your savings; the smaller the meal package, the smaller the savings. I personally don't think that they are a huge enough bargain to worry about; my husband loves them. Of course, he's not the one carefully counting them out to make sure they all get spent. If you don't do a character meal, you'll lose money because you can't get a meal package without a character meal. From personal experience, if you go at a time when the park has shorter hours, you may lose money on some of the breakfast coupons which are only good at the park, and the snack coupons will be hard to use if all of the snack stands are closed.
An AP should get you some discounts on dining. If you're worried about saving up for meals, you could purchase Disney Dollars instead, which can also be used for purchases if you don't use them all on meals. Or you could eat off-site, which is slightly less expensive, and I believe has more variety. (Take this with a grain of salt--I don't eat off-site when I'm there.)