I am a local resident to Cal Poly Pomona and Mt. Sac. Not sure what reviews you have heard about or seen, but the California community colleges are very crowded and getting classes can be an issue. You need to be proactive and do some research on how to get better priority registration (joining the Honors program), be flexible with class times and willing to take some courses during summer session if you get behind. If you have the determination, you will succeed. Also it is not unheard of for students to take classes at several different CC’s to get in all their classes within a reasonable amount of time.
Since Mt. Sac and Citrus College are within my local area, I know many of my son’s friends that have successfully transferred from both schools to Cal States, UC’s and some private Universities.
I recommend you meet with your HS counselor and formulate a plan. You will be required to take some English/Math placement tests prior to enrolling in the community college so if you get your act together early and prepare, you should be all set to move forward towards your goal.