Before saying that all is OK now, go through a few checks and maintenance steps, then keep your eye on things.
Top up the battery cells,
Check and adjust the fan belt tension,
Make sure the charge warning light is:
On when the ignition key is in the run position with the engine off,
Off when the engine is running, and
Off when the key is removed from the ignition.
If you only drive the car a mile or two each time you start it, you can expect the battery to run down.
While charging the battery has restored your ability to start the car you need to make sure the car's charging system is really working. A fully charged battery can start and run the car for quite a while (even with a completely dead charging system) as long as you aren't using a lot of things like headlights that draw a lot of current.
It's okay now, but as above, you may get a repeat, follow the advice of the experts and check the items above.
I'd add to that checking engine and battery earth straps for condition, they can fray and cause all sorts of issues.
Maybe once a week take the car for a longer drive on the way home from work, 10 to 20 miles of driving to give the oil a chance to warm up and get round the engine, and also give the battery a good charge, it'll do a lot more good then damage. And it'll be good fun!
Dave
Good luck!
