Baby, you're a firework. Come on, let your colours burst (song reference). Here's a short tutorial on how to create fireworks in Adobe Photoshop.
Step 1: Opening up the file
Start off with opening Photoshop. Once you have Photoshop open go to File>New. Choose the photo option from the drop down menu. Click on the paint bucket and change the colour to black. Now click on the background and make it black. Finally create a new layer. Now you are ready to start creating fireworks.