re: Just got a bike and have some general questions

It may be. I checked for slack in the chain by pulling the chain out from the main chainring and there is some play.

I’ll plan to keep riding as is until I can grenade the current crankset lol. Been researching all day and it just doesn’t seem worth upgrading these 20+ year old components until I have a real reason to do so. As cdawg mentioned, tires would probably suit me the best right now.

Edit: saw your edit. Yeah, some of the teeth on the main chainring don’t look right, but lots of googling suggests that could be by design for shifting. Overall the teeth do have wear, but I wouldn’t say they’re trashed. Should have some life left. I’m seeing it’s a Shimano Alivio FC-MC14 crankset, assuming replaceable chainring but not 100%.