1998 Chevy Lumina Having some type of electrical problem?

My lumina will startand run fine for a while and then out of nowhere when you get in and try to start it it acts like the battery is not working properly for instance the door dinger will ding wierd and the lights will dim but then if you keep playing with it then it will eventually start. Then today I went to go start it and the locks started clicking and it wouldn't unlock (power locks) and my alarm was going off but not loud just sounded like a light sputter. I couldn't get the alarm to shut off for about 5 min then pressed the unlock button a few times then locked it again and then unlocked it again and now it works fine? Any ideas by chance? Please lol