You're OK. You don't need to do anything else as long as you followed the drop rate. You can mow in a few days.

Can I water today then? Thanks!

The label should say when to water, probably 24-48 hours after application. The reason for watering beforehand is to get the weed control granules to stick to the weed leaves. It needs to sit on damp leaves, dissolve, and dry out for a period of time. Once dissolved and dry, watering afterward will allow the dissolved weed killers to be absorbed into the weeds. In theory anyway...you'll get much better results spot-spraying or using a concentrated weed killer in a hose-end sprayer, unless you inspect every weed and make sure the granules stuck to them.