The laptop should have come with CD/DVD burning software preloaded. Acer's specs page
for your model says it comes with NTI Media Maker. The program will have help information available to guide you through, and you can find more help online. If you just want to write data files onto a DVD, the process typically is not much more than dragging files to a layout window and telling the program to burn the disc. This gives you a way to back up data, or to store movies in formats you can view on a computer (AVI, MPG, etc.).
On the other hand, if you're asking how to make a video DVD that will play in a regular DVD player like a commercial movie, maybe with features like menus or scene selection and such, the process for making that kind of DVD is more involved. You need some DVD authoring software. NTI may offer that capability, but I'll admit I have never looked.
In most cases, the software that comes preloaded on computers is a limited version of some commercial product. The computer manufacturers get paid to include the program, and the software company hopes you'll buy the full version when you discover the limitations. If you don't want to pay for software, there are free, more full-featured programs available for downloading.
For general CD and DVD burning, I use CDBurnerXP.
To make video DVDs, I use a program called DVDStyler.
Both are open-source, meaning they are 100% free to download and use, and they both offer a lot of features.