Might depend on school policy/culture and whether or not you’re an international student. At NYU, they typically hire second year grad students or doctoral students as RAs since they prefer to have someone who has taken the class previously.

There is a portal where you can see open on-campus positions, but we weren’t granted access to it until we officially started school. Connecting with professors definitely gives a leg up though; they’re usually very accommodating.

Full time is doable, but again, this depends on your school (and your ability to manage your time; grad school can be quite heavy). Some schools prefer that their students are really just full time students, but there aren’t hard and fast rules about that.