Date: 202007
Local time of day: 0001-0600
Location: ZZZ.Tower, US
Aircraft: Small Aircraft; Low Wing; 1 Eng; Fixed Gear
Operator: Personal
Operating under: Part 91
Flight plan: VFR
Flight phase: Taxi
ATC / advisory: Tower ZZZ
Second aircraft: Small Aircraft
Reporter organization: Government
Reporter function: Local
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Distraction; Communication Breakdown; Situational Awareness
Second reporter function: Single Pilot; Pilot Flying
Anomaly: ATC Issue All Types; Conflict Ground Conflict; Less Severe; Deviation / Discrepancy - Procedural Clearance; Ground Incursion Runway
Detector: Person Air Traffic Control
When detected: Taxi
Result: Air Traffic Control Issued New Clearance; Flight Crew Returned To Clearance; Flight Crew Executed Go Around / Missed Approach; Flight Crew Became Reoriented
Contributing factors: Human Factors; Environment - Non Weather Related
Primary problem: Human Factors

Narrative: Aircraft X was holding short Runway XX for departure. He had an IFR flight plan on file and issued to him but wanted to go VFR. I the Local Controller issued him a VFR advisory clearance. Aircraft X read it back and must have proceeded to line up and wait on Runway XX. I must have noticed him on the runway at about the time he asked for a takeoff clearance. I told him to exit Runway XX and it appeared he started his taxi down the runway to exit at Taxiway Kilo. I sent Aircraft Y around on Runway XY. Aircraft X exited at Taxiway Kilo and I re-cleared Aircraft Z to land Runway XX and that the runway was clear.It's a pandemic. I'm wearing a mask and gloves while working. It's exhausting and stressful. Air traffic around the country has reduced hours we have split up in groups so if one group gets sick the others can still come in after the Tower/facilities are cleaned. Things are not normal but these bored people that want to joyride around in their private aircraft can do that at their will and they have been doing it for a long time even flight training has been ongoing. Flying right now should be with a purpose of going for point a to point b; I don't see why we tolerate people to joyride/flight train during this time. Why can't everyone be IFR and fly with a purpose of moving people/doctors/equipment or whatever from point a to point b. If we banned VFR flights I'm sure the joyriding will stop.


Second narrative: I was at hold line for Runway XX; decided not to go IFR told Tower I wanted to depart VFR.With VFR advise; Tower said he would have to cancel my intended flight plan -- and give me a squawk.  As I was waiting for a plane to land and clear runway; Tower came back to me and said 'squawk XXXX and in turn east remain below 2;500 feet and contact departure on XYZ.A.'   I then waited for plane to exit runway.Then taxied onto runway thinking I had been cleared for takeoff. [I] realized that I had not been cleared for takeoff and Tower was open (right now Tower [is] on limited hours and have been flying a lot with no Tower). Realized error that tower was open 'called Tower and they asked me to exit the runway immediately;' there was no conflict.


Synopsis: Tower Controller and small aircraft pilot reported a runway incursion resulting in an aircraft having to go-around.