Ya ho~ Nya! First Day

Nya~ Feel free to flame me...i'm such a moron. This is my first blog nya~

I made this eact thing about 5 minutes ago and then deleted it because i freaked out about my email being my username and wah~~~~

The sole purpose of this blod is to find out what he is!
<---- Yes him, the cactus i named Chris after the person who bought it for me.
I have no idea what the species is -and no the net didn't help, it just hurt my head-, or how to look after it and well you get the idea...

It keepes leaning to one side, and then i noticed the soil was detached somewhere in the middle, and i think it needs a bigger pot, and he's starting to get a little bit yellow on some part, which i think is over exposure to the sun...also my mum insists on putting it in another pot, since that one has holes in it and when wtared...well you get the point. So he's also put inside another...which bends and brakes his spines/spikes (yes i know nothing about cactii, not even the proper terms).
So what i really want to know is how i can look after him and what species he is... I wanna stop him being cramped and turning yellow nya! Q-Q I fail at being a cactii carer....

I hope someone can help me and my fail attempts at this ^^