My guy was a little over 2 when we started, we made up a potty chart (a train one) got his favorite stickers (Wiggles) and I gave him a sticker for sitting on it the first day. Second day, that morning, plopped him on it naked and distracted him for 20 minuites with books and stickers and etc....then let him have a sticker. Did that the next day too, no success either time. The third morning, after about 15 minuites, he started peeing. He had the most STARTLED look on his face, but when I clapped and cheered and hold him he could have a bunch of stickers, he realized, each morning that it was ok to pee in the potty. After about a week of that, the times getting shorter and shorter where within just a minuite, he'd pee, we tried doing it off and on during the day. Poop was the same, first time was a total accident, and he looked freaked out, but when I got excited, he was too.
My tips, are give him stickers, as many as he wants. He does two drops, gets a sticker, does two more, gets a sticker, that's ok! One time he stopped his pee a half dozen times to get stickers. M&Ms too were helpful for getting him on the poppy, when he didn't want to sit. Be patient, sometimes it takes a half hour sitting there at first til they are comfy enough to realx and pee, so be sure to entertain with books or small toys!