or not.
they are predefined events. once done, they are gone.
individual groups of gang members standing around, gang fights, police in need of help etc, may be procedural, but they are not like real activities and more like minute random encounters. they also don't show up on your main map, nor do they offer any more than the eddies and exp you get from the bounty on the people.
Once you get into the open world, you do not have to rush to any of the main quests, even if they make it sound urgent. Instead you can just walk around Night City and clean out as much of the side activities as you like (if you can manage). I even advise you do so, for some better gear and some exp. It looks overwhelming at first glance, but most are rather short and can be done in a few minutes.