General aviation pilot reported a near miss with another aircraft while maneuvering into the traffic pattern during visual conditions. The Controller could not maintain the distance between the aircraft and issued a go around to provide separation.

Narrative

I was flying in from the north having taking off from ZZZ. I had been cleared direct ZCARR just short of winslow. approaching ZCARR I was vectored by Approach to SDL. I had the weather and NOTAMs and expected the visual approach into SDL. As I got within 10 miles of SDL after coming over the mountains at 7;000 from the north; Approach asked me if I had the airport in sight. I was unfamiliar with the airport so waited another minute to confirm. when I did I was switched to SDL Tower who cleared me for the Visual 21. I replied that I felt I was too high and wanted to delay to get down to pattern altitude of 2500 because at this point I was just 5 miles from the airport and still at 4;000. I guess I could have specifically asked for a delay vector but did not. The Controller then suggested I fly a midfield right base. I was trying to process that because for me that meant crossing over the airport midfield and turning downwind but that was a left base. I did not know how to question the Controller's request or just say unable. Was I on a different side of the airport than I thought? So at that point I was over the field reporting midfield at 3500 - i was going to turn left for a left base. Which I realized was not what the Controller said but did not know how to push back. That is when the Controller said descend immediately to 3;000 which I did immediately. above me was Aircraft Y no more than 500 ft above me crossing over top of me on a left base. The Controller then told me to follow Aircraft Y as #2 on final and watch for wake turbulence; which I did. I planned to land a bit further down the runway to avoid the wake turbulence. However because we were so close as I followed him and he slowed down to land there was not much distance between us so as I approach 1 mile final Controller said go around which I did. I made a go around to the right; was cleared to land on 21 and made an uneventful landing. Suggestions:1) do not over-focus on trying to find an airport for too long ignoring altitude and pre-landing altitude. I knew the pattern altitude was 2500 but did not descend quickly enough to be in a good position to land. 2) If not clear about Controller's intent; State 'Unable'; or specifically ask for delay vectors; or actual vectors to final. Not sure what terminology to use to ask Controller to clarify. Remember I am PIC and if I don't want to do something I have final decision. 3) realize that Controller never said 'enter midfield crosswind' Controller just said 'fly midfield for the right base' which I think was to fly midfield then turn left for a right base. I think Controller could have accepted I needed more time; or sensing I was not really setting up for a midfield downwind; intervened before I crossed midfield because Controller knew I was too high before I got to midfield to make a turn and land; and given me a delay vector ....though I know its a busy airport.