I never wear blush, but i'm just wondering if it's bad for your skin.
And also, i have terrible acne that seems to be spreading on my cheeks. I wear conealer which is suppose to help treat acne. But i'm wondering if it can also clog pores and cause break outs?

It can if it's not the right kind. Usually there are types with salicylic acid, so make sure to use those.

Your skin is always better off just breathing. If you're just staying at home, don't use the concealer. No matter what it says, it still makes pimples take longer to heal than just letting them be natrual. But if you are going out and need make-up, just use a good, oil free brand. I prefer a powder blush over a creme, as the creme tends to be shiny and more likely to clog pores. Try and get everything in oil free. And wash off your make-up the very moment you get home! NEVER ever ever sleep in it!