One of the most common issues you'll have to deal with when shooting in all sorts of genres is the noise that comes from shooting at higher ISOs. This helpful video will show you how to effectively remove it in Lightroom.
Coming to you from Unmesh Dinda of PiXimperfect, this great video will show you the ins and outs of removing noise from a photo in Lightroom. As Dinda demonstrates, one of the best tricks for working in the Detail panel is holding the alt/option key while adjusting a slider. This normally triggers Lightroom to modify its display of the image in some way that makes it clear where and how much the current slider's function is being applied. For example, doing this while adjusting the masking slider will show you exactly where sharpening is being added, making it easy to ensure you're just applying it to prominent edges and not increasing the appearance of noise in broader areas. When you're working on this, remember that in general, it's a tradeoff of keeping detail vs reducing noise (though there are some techniques to tip the scales a little more in your favor), so always keep your eye on the image and adjust it to taste; there are no universally correct settings.