When you are a novice just practice the basic combo's. Before my fights my coach always says to me, "do the basics, do them well, and do them often" Get the basics off to a tee before you start adding in more complicated stuff. A good crisp double jab and lateral movement will get you a long way imo.
If you are in as position where you are asking this question on the internet... stick to the 3 basics you mentioned.
Also,mix in feints with your combos to become more unpredictable. Ex.Feint a hook then throw a 1-2,or feint a 2 then throw a left hook,right uppercut.
