How much do ECs matter/am I overloading my self?

I’m getting IGETC out of the way first, this semester I’m taking 5 classes (intro chem + some humanities etc.) and luckily all my proffesors are well rated and the classes sound interesting. I got a lot of classes cleared out just from Ap scores. I am worried however, as I took 3 CC classes during high school, didn’t try at all, and flunked them. They’re not transferable but I’m not sure if I have to list these classes on my applications or get them expunged or what.

Anyways, on the the question. My goal is to TAG to UC Davis for design, which I was rejected from as a freshman (boohoo.) Between the uncompetitive nature of my major and the advice of a transfer counselor, there’s not much I should do other than complete IGETC, take the whopping 5 prep classes my CC offers (other local cc offerings are not much better), and get good grades. However, I know ECs count in regular applications. Here’s what I have lined up:

Volunteer at a prominent Bay Area museum (2x a month, 96 hours a week) not sure of this because it’s a bit of a commute

Teach English to adults at a local library (1-2x a week)

Teach English/American culture+ sewing skills and other things to SIVs/Army interpreters. (1-2x week)

I do not intend on working while enrolled at cc as I feel that there is a huge surge in need for volunteers.