I agree with H. Smoke and Ermac. Their easiest combos can be upgraded as you improve.
~Example~
H. Smoke: spear, HK, LP, (walk forward) aaHP, spear, HK, LP, JK, airthrow.
After that gets too easy you can change it up. Instead of aaHP do a tele punch, change the 2 hit pop up at the end to 3, etc.