UCSD Freshman - need course advice

I’m an incoming freshman majoring in Neurobiology and need some advice…
I took the chem placement test and was recommended to enroll in Chem 6A. The thing is, I can only take that course if I’m concurrently taking Math 10A/20A. I was recommended to take Math 4C. I’m taking the MPE today - I know… super late as enrollment starts on the 28th. I’m not very confident in my math skills and feel like I would be more comfortable taking Math 4C and Chem 4. I read on UCSD’s website that it’s not bad, but that it might hinder my “four year plan” to graduate.

Is it bad if I take Math 4C + Chem 4? Is it possible for me to take courses for credit over the summer before soph year to “catch up”?