C150 pilot reported an near midair collision with another small aircraft in the pattern.

Attributes
ACN	1460065
Time
Date	201706
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Cessna 150
Operating Under FAR Part	Part 91
Flight Phase	Landing
Route In Use	None
Flight Plan	None
Aircraft 2
Make Model Name	Small Aircraft
Flight Phase	Landing
Person 1
Function	Pilot Flying Single Pilot
Qualification	Flight Crew Private
Experience	Flight Crew Last 90 Days 5 Flight Crew Total 75 Flight Crew Type 67
Events
Anomaly	Conflict NMAC Deviation - Procedural Published Material / Policy Inflight Event / Encounter CFTT / CFIT
Miss Distance	Horizontal 50 Vertical 400

Narrative:

Coming into ZZZ this morning I was instructed to look for traffic. I got a visual and radioed that in. Tower then told me to follow that traffic and that I was cleared to land runway 28R; number 2 in sequence.so I followed the plane and then when I turned final I saw another plane below me pass me and land on 28R. I called tower and told them there's a plane on the runway. They had me take an immediate crosswind turn to the right and cleared me to land again as the other plane was doing a touch and go.in the confusion; instead of retracting flaps; I had fully extended them when executing the go around. I was losing altitude even with full power and was below 40 knots IAS just a few hundred feet above a lake just north of the airport. Tower called to ask if I was ok.finally found the flaps fully extended; retracted them; and landed without incident.I believe the airplane I was supposed to follow was a different airplane than the one I saw and followed. My guess is that the one I saw was operating on the parallel runway; 28L. I mistook that airplane as the traffic to follow and so turned to base and final too soon. Fortunately the airplane I was supposed to follow reached the runway before I had fully turned to final.

Original NASA ASRS Text

Title: C150 pilot reported an NMAC with another small aircraft in the pattern.

Narrative: Coming into ZZZ this morning I was instructed to look for traffic. I got a visual and radioed that in. Tower then told me to follow that traffic and that I was cleared to land Runway 28R; number 2 in sequence.So I followed the plane and then when I turned final I saw another plane below me pass me and land on 28R. I called Tower and told them there's a plane on the runway. They had me take an immediate crosswind turn to the right and cleared me to land again as the other plane was doing a touch and go.In the confusion; instead of retracting flaps; I had fully extended them when executing the go around. I was losing altitude even with full power and was below 40 knots IAS just a few hundred feet above a lake just north of the airport. Tower called to ask if I was OK.Finally found the flaps fully extended; retracted them; and landed without incident.I believe the airplane I was supposed to follow was a different airplane than the one I saw and followed. My guess is that the one I saw was operating on the parallel runway; 28L. I mistook that airplane as the traffic to follow and so turned to base and final too soon. Fortunately the airplane I was supposed to follow reached the runway before I had fully turned to final.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.