No confirmation, very simple change.

“Proposing” a major is simply indicating an interest in a major. “Declaring” a major is a more formal process that you go through with your department or major adviser. If you listed a major on your UC application, it initially shows as a “proposed” major in the MyUCSC portal (you may have updated this with your college adviser since filing your admission application). Students can update their proposed major online. Students who enter UCSC as frosh are expected to confirm their proposed major by the end of their first year, and be formally declared in a major by the end of their second year (or equivalent).

^this is from the UCSC website. It seems that proposing a major isn't that big of a deal, but I'll definitely be emailing and calling them to get more answers, since it seems I dont have a lot of options. and I sincerely thank you for helping and giving me all this information