To clarify what I meant by takedown and stand over him, what you're going to do is run up, takedown, you'll be held down in his guard and you'll press the left stick in and it'll stand you up. Press the stick in again and do a short sprint towards him before he gets up, and you're standing over him while he's on his back attempting to guard himself. That's when you start punching him.
It might take a couple tries to get him to stay down but generally you should be able to do it within 3-4 attempts unless the CPU is being really douchey. As for playing on beginner your modifier for sparring points is fairly low and if you haven't gotten the takedown/punch thing down to something you can do in your sleep yet you won't be seeing a TON of points but it's much more than you would sparring regularly.
I would recommend switching to experienced over beginner, the only difference is the CPU fights are slightly more difficult but your sparring partner is still borderline retarded.
As for what I meant by slam, later in my fighters career I tried the suplex from clinch I believe it's from double underhookers, you press forward on the right stick it takes you directly into the underhooks and then you just roll the stick while pressing LB to slam them. Either method works fine.