Congratulations on getting your first period!
I am a little confused though... if you got huge cramps, you should know that generally they tend to hurt quite a bit!
Cramps are usually very painful... if you aren't feeling pain then what you are probably experiencing is the general bloated, swollen feeling that many women get in their lower abdomen during menstruation.
Cramps also vary in severity, some are quite severe, others are a dull ache and a some lucky few don't experience them at all!
It is a very individual thing! If having cramps are likely to make you even more cranky then you can always use some painkillers to fix the problem!
Crankiness is not something you can do much about other than be aware of it. If you are aware that you are in a not-so-nice mood then steer clear of others until you are feeling better. If you are in a situation where you are forced to deal with other people then just be aware of it and try exercise some tolerance. You need to learn to be in control of it.