IIRC from BYC you are in the Phillipines or something like that? I have no idea about specifics outside of eastern N America, sorry... but, look around and see what are the commonest things for other people to grow, those are usually the easiest things
In general, though, leaf veggies and squash/melons and bean/pea type things are usually among the easy ones.
Also tomatoes and peppers if you get already-started plants (not that they're difficult to start from seed, just that it adds another layer of complexity is all). Fruits mostly take longer to start bearing - I would not plant them til you've spent a year caring for veggies etc and have a better idea what you can cope with and what your soil and seasons are like from a gardening point of view.
The better your soil and the more predictable and sufficient your watering, and the more-adequate your sunlight, the easier ANYthing is to grow. Also, things are easier if you can spend more attention on them, so it is a really good idea not to make your first veg garden too big - try to shoot for something like half the size you *think* you can manage and maybe you will be ok
Your chicken cleanings will have to compost for AT LEAST 3-4 months before you put them on the garden. Ideally they should be about half poo and half shavings or straw or whatever you're using. If you still have a sand run, mix the poo you clean out with some dead grass or dead leaves or something, pref. small not large pieces. Don't put the compost on the garden til it is darkish brown and crumbly.
You fertilize growing plants (as per recommendations, now, not just willy-nilly!) either by using liquid fertilizer diluted in water and poured around the plant, or by putting some FINISHED compost around the plant but not within about 4" of its stems. (The nutrients will gradually work their way into the soil, and worms etc will gradually work the compost into the soil too... although for some crops you can hasten the process by lightly ruffling it into the top layer of soil with your fingers or a cultivator). Well ok there are some other ways of fertilizing too but those are the main ones to start with
Good luck, and sorry not to be more help,
Pat