The last thing you want to deal with after a long day at work is a faulty garage door. You have driven home and you press the button to the garage door opener and it goes up just fine. You pull in and hit the button again, but the door does not close. When things we take for granted do not work as we want them to. Thankfully garage door repair is not your immediate first step.
The garage door is a complicated set of pulleys, springs and other mechanical apparatus. Thankfully though the first solution is not nearly that complicated. Check the batteries. Sure the garage door opener worked going in, but dodgy batteries are the most common problem and they do not require garage door repair technicians to be called.
Next, check out the electronic eyes. The garage door will not close if there is something obstructing the eye. This is a safety measure, if something hinders the infrared light from completing its circuit, the door will not close. Maybe there is a shovel or a bag around the light. Maybe there is a leaf in the way or you just did not pull far enough into the garage. Maybe the eye got twisted somehow. Check the eye. Adjust it if you see a problem.
If nothing is in the way of the eye and it is properly adjusted then check the springs, cables and the pulleys. If you see anything that does not look right, stop trying to close the door. This will only exacerbate the problem. If there are issues with the mechanisms this is likely beyond your capabilities and should be handled by a garage door repair technician. In the meantime lock the adjoining door to your house and call the technician in the morning.