I agree with all the posters above.
Yet...
Two years to learn Fur Elise?

I guess it is better than the ABRSM forecast of five years (it is considered a grade 4 piece).

Here is how a total beginner can learn it after 12 practice sessions – each practise session lasting around 20 minutes, so if you cram 6 practise sessions in a day (=2 hours practice), you can be playing it at the end of two days, rather than two years:
Session 1: Bars 20-24 (Add 1st beat of bar 25. These are difficult bars).
Session 2: Bars 1-5 (These bars are repeated 15 times in the whole piece).
Session 3: Bars 1 – 16 (Add 1st beat of bar 17. Bars 6 – 16 are repeats of bars 2 – 5)
Session 4: Bar 45 (Add 1st beat of bar 46 – this is the most difficult session)
Session 5: Bars 17-20 (Add 1st beat of bar 21).
Session 6: Bars 1- 44 (Add 1st beat of bar 45. Bars 24 – 44 = bars 10 - 30).
Session 7: Bars 45-52 (Add 1st beat of bar 53. Bar 45 is particularly difficult).
Session 8: Bars 53-60 (These are difficult bars, extra practice recommended).
Session 9: Bars 1-82 (Bars 61 - 81 are a repeat of bars 10-30).
Session 10: Bars 82-99 (Bars 91 - 99 are almost a repeat of bars 83-90).
Session 11: Bars 99-105 (Add 1st beat of bar 106. Difficult bars).
Session 12: Bars 1-126 (Bars 106-126 are a repeat - almost - of bars 10 - 30).
Or do a session a day, and we are talking 12 days.
Now, unfortunately this schedule assumes that I will be at your side during all these practise sessions showing you exactly what to do. Since this is not the case, expect it to take far longer. (It may well take two years to get to the stage where you can learn it in two days - you see, learning Fur Elise is not the real problem.
Learning how to learn Fur Elise is what takes time).
In the meantime I strongly suggest that you read through Chang’s book here:
https://members.aol.com/cc88m/PianoBook.html(where he suggests a very similar approach and goes into a lot of detail about Fur Elise) and start acquainting yourself with efficient practice methods.
And forget the concert for the moment (you will need an orchestra willing to play with you for a start – so concentrate on the solo repertory for the moment being)
Best wishes,
Bernhard.