Creating footprints can be confusing if you're just getting started and don't know what they really are. In this video I explain what a footprint is and the overall process you can always rely on to create your own footprint for a printed circuit board.
This process is applicable regardless of the electronics computer aided design (ECAD) software you're using. So if you're using Altium Designer, Cadence OrCAD, Cadence Allegro, Autodesk EAGLE CAD, Mentor Graphics PADS, Zuken, KiCAD, etc. It doesn't really matter.
You can calculate the footprint first based on the device data sheet dimensions, the IPC-7351B standard and/or a free calculator created by PCB Libraries. Here are the articles and links I mention in the video to help you design your own footprints based on data sheet information.
What is a footprint?
What is the overall process you can use to create footprints?
What rules govern industry standard calculations for PCB footprints?
An automatic footprint or land pattern calculator for electronic devices
Please note that you don't HAVE to build footprints exactly to IPC standards, though I do highly recommend doing so.
Even better than the standard, oftentimes is the Recommended Land Pattern for a PCB footprint you find in a data sheet. If you see a recommended land pattern, skip the IPC stuff and use that footprint instead.