How to Improve UMvC3 techniques-Ways to Practice?

First off, this question MAY be too basic.

I recently purchased UMvC3 for the PS Vita. After fooling around in training and playing Heroes and Heralds for a while, I decided to go online to strutt my stuff. I was beaten mercilessly.

I tried some missions, and even those felt too hard, performing complex combos with precision and speed. So here is what I’m asking. What are some good strategies to get help? Should I choose a good team of three and memorize the movesets? Should I practice techniques such as blocking and cancels(Not a total idiot!) in training against the CPU? I’d like more of an in-depth answer, and anyone who is willing to help me via an online match, send me a message on PSN.