How do I ride a horse??

So. My dad and my uncle are getting our horses back into shape. they haven't been ridden in a long time. they go for rides about twice a year. but we are hitching them up more often now. I wanna try ride one bareback or something. But the good one bucks every now and then. I caught them both and they are really frisky and it took me like 20 mins and takes my dad and my uncle sometime cause they run all over the place. How do I train the horse so he will let me ride him bareback or something.?