To play your movie, press the Playback button on your Nikon D5300. In single-image playback mode, you can spot a movie file by looking for the little movie camera icon in the upper-left corner. You also can view other movie-related data, including the Frame Size, Frame Rate, and Movie Quality setting. (A star means that you set the Movie Quality option to High.) To start playback, press OK.

In the thumbnail and Calendar playback modes, you see little dots along the edges of image thumbnails to represent movie files. This time, press OK twice: once to shift to single-image view and again to start movie playback.
After playback begins, you see this data. The progress bar and Time Elapsed value show you how much of the movie has played so far; you can also see the total movie length.

The other symbols at the bottom of the screen are there to remind you that you can use various camera buttons to control playback, as follows:
Stop playback: Press the Multi Selector up. The white circle labeled Playback control symbols (lower-right) represents the Multi Selector.
Pause/resume playback: Press down to pause playback; press OK to resume playback.
Fast-forward/rewind: Press the Multi Selector right or left to fast-forward or rewind the movie, respectively. Press again to double the fast-forward or rewind speed; keep pressing to increase the speed. Hold down the button to fast-forward or rewind all the way to the end or beginning of the movie.
Forward/rewind 10 seconds: Rotate the Command dial to the right to jump 10 seconds forward through the movie; rotate to the left to jump back 10 seconds.
Advance frame by frame: First press the Multi Selector down to pause playback. Then press the Multi Selector right to advance one frame; press left to go back one frame.
Adjust playback volume: See the markings labeled Volume control symbols? They remind you that you can press the Zoom In button to increase volume and press the Zoom Out button to lower it. The number value tells you the current volume level (10).