Time to learn my first piece (hopefully)

Hey, I took about three months of piano classes last year, I only got to playing exercises and reading sheet, I got comfortable with my right hand and am still struggling a bit with my left but I couldn't keep taking the classes and now I sort of lost motivation a bit, so I wanted to try pushing through and learning Pavane pour une Infante Défunte which is the reason I started taking classes. Is that a bad idea? I learned guitar by doing that with crosses by José Gonzalez and just kept learning whatever I needed, so does that work for piano or will I create a bunch of bad habits that I'll never get rid of? Also, any tips on learning pieces for the first time?