Please help me

I am a Biology major at a community college who wants to transfer to ULCA, and then on to dental school. I am being told that I need to take classes such as o chem and other pre- to transfer, but I feel that this would hurt my chances of getting into dental school. Is it a good idea to change my major to something that doesn’t require me to take me pre-reqs, and then when I transfer I change my major back to biology.

That’s correct, you need those prereq courses to transfer as a Bio major. Check Assist.org.

It’s almost impossible to change majors after transferring to UCLA, especially if it’s in different colleges/departments.

If I am not mistaken, I think you need organic chemistry and some of the other hard science prerequisites before you can apply to dental school. These are lower division courses (before your junior year). You should check.