Korean help

Hi everyone, how would I say the following:

1. That i am a student, and that I am studying Korean?

2. That I like to learn languages?

3. How would I say that I am studying to become a psychologist, is there specific word for that or 'therapist' in Korean?

4. I'm still trying to get a better handle on the particle markers, and I must admit I find it confusing to know when to use which pair! like:

'eun/neun' and 'i/ga' um...oh, and 'eul/reul'

If anyone has any advice on how to get these straight, I would so appreciate it! Is there a set rule or pattern to follow for these, that i'm just simply not aware of?

5. Is there a word for 'chocolate' and 'vanilla'? There is a Korean bakery that sells different coffees, cakes, etc and I'd like to know how to ask for either/or variety. =)

Chongmal kamsahamnida!