A torsion spring under load can put someone in the hospital - that's not scare language, it's physics, and it's the one repair on this list we won't walk you through over the phone. Cables, drums, and anything that involves the spring system is a no on the DIY list, full stop.
Things you can reasonably check yourself: whether the opener has power, whether the safety sensors at the bottom of the tracks are aligned and clean, whether the track itself is visibly bent, and whether the door is binding on one side versus lifting evenly. If the door won't budge and you can see a gap or a snapped coil in the spring above the door, stop there and call. If it's just a sensor knocked out of alignment by a bike or a trash can, that's a five-minute fix most people can do without a truck showing up.