We are coming up to color and tonal adjustments. First off, to adjust the colors correctly, make sure that images displayed in Photoshop look the same way as on your target output device.
Open Color Settings dialog box (Edit > Color Settings...). Photoshop offers to select from a number of options. As a beginner, just select a preset from the "Settings" menu.
For example, if you produce images for press, select "Your Region Prepress".
If you are a web designer, select "Your Region Web/Internet".
If you are not sure what settings are right for you use "Your Region General Purpose".
NB For simulating CMYK colors or some specific output device you use "Soft Proof".
