How do you practise on a skateboard?

i'm 25, and i know what you're going to say, OMG, you are waaayy to old to be learning how to ride a skateboard, but i've always wanted to learn, and never really got the chance. I found one pretty cheap in kmart (good for just first time learners like me). So when learning how to skate, how do you practise, without actually falling down? I tried skating around whilst holding onto the wall inside the house (on carpet not floorboards) then i got bored, and rode a little bit outside on the pavement, and fell off straight away LOL. I don't like falling, on account that i fall heavy hehe. And if you were to choose between any boards (normal, ripstick, long, etc), to do all your actual first time learning on, what would be easiest?