Some of this you can check yourself before calling anyone. If the door won't close, look at the two small sensor eyes near the floor on each side of the track - if one has been bumped out of line, the opener will blink and refuse to shut, and that's a five-minute fix with no tools. If the remote does nothing but the wall button works, it's usually a dead remote battery, not the opener.
What we don't recommend touching yourself: the logic board, the motor itself, or anything involving the opener's internal gears or capacitor. These units carry stored electrical charge even when unplugged, and on older chain-drive models the gear housing is riveted shut for a reason. We also don't recommend ordering a replacement opener online and installing it yourself if your current unit is wired into an older breaker setup - a lot of the wiring in houses from the 1960s and 70s wasn't run with a dedicated opener circuit in mind, and that's worth a second look before you add a new motor to it.
If you've checked the sensors, checked the batteries, and it's still acting up, that's the point where it's a diagnosis call, not a guess-and-replace job.