Confused about what and how to eat

For a while I was doing intermittent fasting which let me lose a lot of weight but I just want to do it in a healthier way now and I’ve started exercising but it seems like a waste of time to exercise but not eat enough to gain anything from doing it. And I’d just like to be able to lose weight while actually gaining muscle from it. Sorry if this questions been answered a bunch of times and also if there’s any strict diet things I think I can do it, I was pretty strict with the intermittent fasting