I watched a good part of this video today. The first person/s he shoots in the car lot or parking area were also chasing him. They appear to throw things at him. Possibly Molotovs. Maybe bricks/stones. That video unfortunately is not as clear. He does make a phone call at this point saying he shot someone, possibly to 911, no way to know from the video I saw.
The second video where he trips and falls, the guy he shoots in the chest swung a skateboard at him and hits him in the shoulder and head. Then the guy he shoots in the arm was pointing a handgun at him. This part would most likely be self defense. The issue is the first incident which is just before he is being chased and falls could alter that.
With a good lawyer or proper investigation/reasonable DA this may all be self defense.
All that said. Pretty dumb for someone to put themselves in that situation. He traveled apparently 20 miles across state lines to be there. He should have stayed home. I’d think differently about someone who was had a home or business in the area.
Then there is the whole issue of a 17 year old crossing state lines with a firearm, and I thought ARs were regulated in IL where he supposedly lives?