Shouldn't be too hard given you'll be attending CMU. There are massive career fairs that happen at top schools. Most, if not all, major companies regularly visit 6-7 schools and CMU is one of them. Age should not matter (Equal Employment Opportunity act), unless you did absolutely nothing from the time you graduated bachelor's until now. You must have good communication skills, enough to be a potential great team player. However, some companies do not usually interview international non-PhD students and they won't even accept your resume at a career fair (I recall IBM was one of them along with Dell and defense contractors such as Lockheed Martin)