I applied to uci as a computer science/engineering major but was put in undeclared, whereas riverside just accepted me right away as a computer engineering major. Does this mean that for my first year I will be doing nothing related to what I want because of the prerequisite courses at irvine while at riverside I can jump right into it?
UCI admits into the school first then into your major. If you did not specify an alternate major, you are placed into Undeclared. Since you are not in the CS/Engineering major, you will not get priority in registering for any of the major related classes but you can still take any of the pre-req courses so you can eventually try to switch your major. Remember meeting all the major critieria is no guarantee you will be able to change majors later.
How to change majors for CSE:
Computer Science and Engineering
Requirements Description
Cumulative UC GPA
2.7 overall and 2.7 quarterly GPA in the quarter immediately preceding the change of major request.
Course grades
Minimum 3.0 GPA in prerequisite courses:
Math 2A-B-D
Physics 7C-7D, 7LC-7LD
ICS 21-22 or CSE 31-32 or ICS 31-32 or CSE 41-42
Other
Students admitted to the major in Computer Science and Engineering will be assigned to the Donald Bren School of Information and Computer Sciences or The Henry Samueli School of Engineering based on enrollment.
Students with more than 90 units will be reviewed on a case-by-case basis, provided they have made substantial progress in courses required for the major.
Unless UCI’s program is very different than UCR’s and you believe UCI is a better fit, go with the direct admit at UCR.