Question about the supplementa im taking.

I am currently taking:

Vitamin C 1000mg

Magnesium L-Threonate 2000mg

B12 2500mcg

And I plan on taking D3, Niacin, and Zinc. The goal for me is to have a stronger immune system, reduce/remove brain fog, and improve my sleep.

My question is if I should avoid any of these supplements or if I should add to it? Also, do any of these supplements negatively affect one another?