Lubricating hinges and rollers with a garage-door-specific lubricant, twice a year, is worth doing yourself - it's cheap and it's low-risk. Tightening visibly loose bolts on the track brackets, same thing, as long as you're not touching anything under spring tension.
What you shouldn't touch: the torsion spring itself, the cables, or anything that requires taking weight off the door. On a door this age, the spring is wound to a tension that's genuinely dangerous if it lets go while you're working on it, and a 1990s spring has had thirty-plus years of cycles on it already - it's closer to failure than a new one, not further. If the door won't stay put when you disconnect the opener and lift it by hand, that's a spring problem, and that's a call, not a project.