Observer reported a weather balloon being launched without a NOTAM. They also observed a UAS flying over crowds.

Narrative

We were tasked by public officials to track a weather balloon launched from private property north of ZZZ for a local school to recover payload. Upon arrival at launch site; we noticed there was no flight plan presented; the operator stated a NOTAM was made; but we couldn't find it. The launch time was initially set for XA:00; but the actual launch was XB:13. Nobody had contact with local ATC during flight and there was no altimeter available during the flight. At least five aircraft entered the launch area including two general aviation aircraft and two commercial airliners. Observing the balloon; it did not appear to have two flight termination systems or a designated radar reflector.During the event; there was also a local drone pilot taking images. The drone pilot stated he needed to file a LAANC to take images of the launch and the school students. The drone pilot was flying a quad copter. He spent about 90% of his time looking at the screen instead of where the drone was operating. During the event; the drone drifted over the crowd of school students multiple times; and each time the pilot was staring intently at the video screen instead of keeping track of the drone.The first attempted balloon launch failed to take off. When the students lightened the load the balloon took off slowly. The initial recovery area was supposed to be in ZZZ1; but as a result of the mass change the balloon traveled more than XXX miles into western ZZZ2 before it burst coming down in ZZZ2 on private property.