Whether creaking is OK depends partly on your tolerance. But creaking synchronous with crank rotation can also be an indicator of a problem. The most common and urgent, is a loose crank arm, which if not attended to can get worse until it becomes unrepairable. It could also be anything from loose pedals (serious if very loose), loose BB cups, or other things that should be attended to.

Whether you're willing to accept the creaking (some can be very hard to pinpoint and fix) or not, you should at least take the time to check that all is good. Start by removing the pedals, cleaning the faces where they meet the crank am and replace (or try another set of pedals), checking that crank arms are tight, and that the BB is tight by jiggling one crank arm and seeing if the movement tranfers to the other. Creaking under load can also be axle flex, or even a broken rear axle (#1 cause of problems on my old commuter).

When you've confirmed all is OK, you can consider the typical crak as normal, and discount it until/unless it gets worse.