Alternator

I have a 1995 Ford F-150, recently I was going to the gas station I left my house and the truck
turned right on as usual, but I'd been noticing an issue with my ignition lock and it would become
hard to unlock it, I get to the gas station and when I tried to turn it on again it just clicked and all
gauges read nothing and not lights it appeared my battery was dead, I popped the hood and
disconnected  my negative and reconnected it and it sparked and then I when I turned the key it
started up. All the gauges read normal exept the battery gauge was moving around reading higher
but still in the "normal" my truck started idling louder even when I had been driving it letting the
battery charge, later on I started it again it turned on and everything was normal, I drove it to the
store and the same problem It clicked when I tried to turn it on, I tried disconnecting the negative
again and that did not work I jumped it and that did not work either, I was then waiting to get my
toe truck service to come use a jump pack because maybe a little car did not have the power to
start my truck I would have my truck towed home if it didn't start, while I'm waiting about 20
minutes go by and my key had been turned to the on position and all the lights came on and I
could start it, ( when I tried jumping it I got no lights or readings on any guages) now it's in my
garage and it started last time I went to see if it would, I don't know what it is a bad alternator or
maybe a started?