I'm 5'8" and weigh 214 lbs. I'm doing the 16/8 IF and was wondering how many calories I should take in in a day.

You should try an app, like MyFitnessPal, to help determine how many calories you should take in. There are more variables than what you've given here that you should consider, like how fast you want to lose the weight. These aren't 100% reliable, as they don't really measure metabolism, but they tend to give you a good starting point, and then you can log your own results and get a better idea of whether you can increase calories or need to reduce them. And I am not 100% sure on this, but I think people choose IF because they don't have to count calories.

Glad you're here! Hope you stick around.