Help beginner 12 variations Mozart

[lebowski]

Hi everyone I just recently started picking up the piano and I know I probably shouldn't be messing around with this piece right now but I heard it and wanted to try to play the first part of it. The sheet music I was reading at first didn't have any marking for trills which was very confusing for me because in many recordings I could certainly hear a trill (even though I didn't know what a trill was). I believe I do now, it's the same two notes repeating quickly starting 1 semitone higher than the note marked for the trill.

The problem is now that I know what a trill is I also found out that some people are possibly doing turns instead of trills for certain areas in this piece that are marked as trills. Then I try to do a trill and a turn in bar 7, 15, and 23. No matter which I do I can't even be sure I'm attempting to play the correct notes.

Help me out here. I believe that in most renditions I have heard of this piece the very first trill is actually being played as a turn. So the piece goes....
                                      Trill/turn
C C G G A A G G F F E E D (EDCD) E C


Then the next part that has a slightly different sound is notated with grace notes on some sheet music and as a trill on others

G G F F D (FDEF) GE D

In any case sorry for the long winded post there are a few other ways I have tried and though about this and I've tried to follow a few peoples fingers online but I just can't be sure and it's killing me!

Please tell me at least what keys are supposed to be played I know I probably can't get it to sound exactly right but I must know!

If this helps this is a link to sheet music without fingering but with the trills marked and the version I'm hearing something that I can't figure out what it is

[j_menz]

I can't make sense of your bar numbers. Do you mean the three trills/mordants in Variation 3?

[lebowski]

No all the sheet music I have been reading has a part that comes before variation 1 which is just the most basic twinkle twinkle little star song except for 3 tiny trills, but it sounds to me like the youtube videos I'm watching are not doing trills, they are either doing turns or something else.

When I say I'm beginning I mean I'm really beginning, like day 5 beginning. I don't plan on trying to tackle this whole thing via forum but I can't get this out of my head.

[j_menz]

OK, I'm with you now. 

I have two versions and neitherr have any ornamentation in Bar 7. In 15 and 23 they both have a spellt out turn (note above, note, note below, note) which seems to me about what onwe would expect.

I suspect some people add additional ornamentation. This is neither necessary, nor, in my opinion, desirable at this point.