How difficult is comp eng.

Im a new student coming to tmu and for various reasons both family and personal I've been really scared to start comp eng. For one my math isn't as strong as I'd like it to be going into tmu, it's enough to get in but for example I barely remember anything from calculus. Should I be worried going in? I don't know anyone online or heard of ever failing or getting kicked out of eng of any kind which is good but then again no one I know did comp eng. I know my worries may seem stupid but it's been bothering me for sometime and I need an answer, not reassurance if it's difficult I want to know. What is the likelihood I fail/get kicked out. Thanks to anyone who responds