General aviation pilot reported a critical ground conflict resulted when they attempted to land on the wrong runway which also had a departing aircraft. Pilot performed a go-around and landed safely on runway as cleared by ATC.

Narrative

I was flying under an IFR flight plan from ZZZ to Denver Centennial (APA). Upon approaching the destination airport (APA); I was handed off to Denver Approach who gave vectoring instruction to approach parallel to the airport from the west (right traffic). I knew to expect one of the Runways 17R or 17L from listening to the weather report at APA. The Denver Approach asked me which type of landing and I stated that I would like a visual approach. Denver Approach then handed me off to the APA Tower who stated that I was approved for the visual approach to 17 left. I confirmed the visual approach approval and instructions. The APA Tower then turned me from right traffic on a right base approximately 7 miles north of the 17 parallel Runways. APA Tower asked me if I could confirm seeing the Runways and I confirmed. This was about XA:20 in the morning and the sun was not very high. Upon confirming the visual approach; I turned right on a 7 mile final to Runway 17 right. At that moment; I remembered the right traffic rule for visual approaches to 17 right and cautioned myself not to turn wide over the 17 left approach path. I concentrated on a stabilized approach and seeing the Runway clearly in the morning haze and low sun on my left cockpit window. The 17 right Runway was clear of traffic on my approach until a plane entered the 17 right Runway for departure. Upon verifying that the Runway was now occupied; I aborted the takeoff. I flew the Runway heading and began an aggressive climb; cleaned up the aircraft and communicated with the APA Tower. I informed the APA Tower that I was going missed. Tower handed me off to approach and I followed instructions to begin my landing process again. The next approach was nearly identical to the first and I landed safely on 17 left. After landing; I was asked to call APA Tower for a conversation and instructions. Clearly; I was given instruction to land on 17 left and did not do so. I was preoccupied with the expectation of a right traffic pattern approach to 17 right as well as chatter on the radio with departing traffic on 17 left. Along with the 2 ½ hour long flight from my home airport over the mountains and the morning sun; I was concentrating on having a stabilized approach and not crossing over onto the 17 left approach in case of approaching traffic on that parallel Runway. At no time; after confirming my visual approach to 17 left on a 7 mile base did the APA Tower reach out or contact me to correct me. I did not confirm my approach after the first time. My radio communication was silent until I called the missed approach to 17 right. I should have confirmed my landing approach with the Tower and more closely followed Tower verbal instruction rather than written right pattern visual approach rules for the airport meant for visual traffic only when the Tower is closed. This could have been avoided with more communication between the Tower and the pilot. I will over communicate and confirm my instructions with approach / Tower in the future.