Using calories

Yes . . . if your profile set-up is accurate, you're statistically average or close, and your logging is sufficiently accurate. If you have a fitness tracker device synched, it will also be necessary that it be one of the devices for which the integration is integrated properly (Apple is iffy), and the device accurate for you (again, that's about being statistically average, mostly - which most people are, by definition).

Yeah, that's a weasel-y statement.

What's often recommended here is that you set things up in a reasonable way, then test-drive it for 4-6 weeks, to see what your average scale weight results are. (Adult women not yet in menopause should test-drive for one or more full menstrual cycles, and compare body weights at the same relative point in at least 2 different cycles.)

If the first couple of weeks of that test period look wildly different from the later ones, ignore those, and use later weeks. (Sometimes water weight fluctuations are weird, right at first, making scale weight misleading.)

Then, compare your average weekly weight loss to the target weight loss rate you set up in MFP. If you've lost around that amount, you're golden. If you've lost slower despite being compliant, and would have room to lose faster safely, cut some calories from your goal. If you lost faster than reasonable, eat more.

To decide how much more/less to eat when adjusting, assume it takes 3500 calories (roughly) to gain or lose a pound of body fat, cumulatively speaking. For example, if you averaged half a pound a week loss, but it would be OK to lose a pound a week, eat 250 fewer calories daily ((0.5 x 3500) divided by 7 days).

My initial estimate was inaccurate, but once I had enough personal data, and adjusted as per above, I lost weight at the expected rate, on average.

It's kind of like running your own fun science fair experiment for grown-ups.

Best wishes!