NEED to add this here:
Playing against the CPU nonstop can develop really really bad habits. Just like playing only online, or playing against only 1 or 2 people. The CPU can not handle complex ideas and can not problem solve well. It can be exploited HARD. If you lack decent competition then play CPU sparingly. It's good for building reaction time, but useless for practicing mix ups. As a side note, thank you Idle for breaking the bad news to me. It humbled me greatly and allowed me to reflect on my fighting style and how I handle situations. Example: Pick Zasalamel. Do only 2A and 4B+K.