Bought a new battery for my bike, will running the bike charge it?

Honda CG 125 2008. Had this issue where the starter motor would just make a click without running. Dismanteled and cleaned the motor, which fixed the problem for like 3 days before it came back. Cleaned the motor again, which didn't fix it so I bought a new battery. Put in it, still just clicking. So I bump started it and drove around for a while. Still nothing. Been driving it around to practice the last couple of days, cause I want to get a full license. But none of it seems to charge the battery. Might have accidently drained the battery once as well by walking away with the key in and lights on. I bought a motorbike battery charger off ebay. Whats likely wrong and what should I do. I have a voltmeter as well, should I measure the volts?