University of California - Exchange student

Hi! I'm a Swedish student from Lund University, just finished my first year and here's some questions about studying in USA.

How many units should I apply for to study full-time?

Are the courses given repeatedly during one semester? One course is a couple of weeks and I'm not sure how to choose courses. Here's an example:

"MCELLBI C103/PB HLTH C102/PLANTBI C103 Bacterial Pathogenesis 3 Units
Department: Molecular and Cell Biology; Plant and Microbial Biology; Public Health
Course level: Undergraduate
Term course may be offered: Spring
Grading: Letter grade. Qualified students may select to take this course pass/not pass.
Hours and format: 3 hours of Lecture per week for 15 weeks.
Prerequisites: 100, 102 or consent of instructor.
This course for upper division and graduate students will explore the molecular and cellular basis of microbial pathogenesis. The course will focus on model microbial systems which illustrate mechanisms of pathogenesis. Most of the emphasis will be on bacterial pathogens of mammals, but there will be some discussion of viral and protozoan pathogens. There will be an emphasis on experimental approaches. The course will also include some aspects of bacterial genetics and physiology, immune response to infection, and the cell biology of host-parasite interactions.
Final exam required. Instructor: Portnoy"

Does it mean that the course is given every 15th week during the whole spring period?

Approximately; how much does it cost to live one month in USA in USD for one month without risk for starvation?

Thanks in advance!

Rokard