Weird motorcycle voltages

So I own a 97 Honda Shadow 600 vlx, 11,000 miles it's got some werid problems. So it's been misfiring when underlow rpm usually when going up a steep hill in to high of a gear or sometimes coming from a stop. Also one morning the headlights started to get really dim like it wasn't charging. My voltages are really werid too. At low idle the voltage reads 12.8v. At high idle with choke on the voltage reads 14.4v. If I rev it higher the voltage drops to 13.5v. Battery voltage reads 12.5v and battery voltage with key on reads 12.1v

Sounds like a rectifier problem which is a common fault with Hondas.

A volt reading at idle should be above 14V right after starting. Clean the terminals connections/cables and check again.

May be a small fault in one of the battery cells so have the battery load-tested at a Shop that does motorcycles.

Check the regulator/rectifier.

For the misfire I would also consider when the valves were last checked.

Those voltages sound quite alright. I think your problem is your riding technique. You are lugging the engine because you ride in too high a gear.

Voltages sound about right. Early Hondas had a weird Voltage regulator which reduced the charging Voltage at high revs too much (unless under load - that's why racers used to fit a low resistance load resistor to the charging circuit to stop this happening.

Check the valve clearances, the air cleaner, if that doesn't work clean the carb.