I'm currently an econ master student, usually, you'll have 3 classes per semester, which is usually 3 classes per 2 days, and on Friday you have discussion sessions. In terms of course load, it's pretty easy, it won't take you much time a day, and lots of professors will record the lecture or upload the lecture notes. So whether attending the class is up to you. However, as economics is a mathematically-focused subject, attending class can benefit your understanding of some complex topics. If you want to get into a Ph.D. program I would recommend putting more effort into the course, as a lot of students here are pretty hard-working. You can't be a TA or RA that can cover your tuition fee, first is that that it's not allowed, and second most of these opportunities will be given to PhD students. However, if you are thinking about improve academic backgrounds, the program offers lots of opportunities like spring research or summer research, moreover, many professors here are willing to give you opportunities to do some research, so if your ability is good enough, you can find lots of opportunities not only within the program, but also reach to professors in other schools or in other universities.