I always teach my students on acoustics first.
First of all, unless you’re Tommy Emmanuel, talking about “limitations” of acoustics vs electrics with regard to beginners is ridiculous, considering 99.9% of people will never scratch the surface of what one can produce with an acoustic.
Second of all, and more importantly, you have to build up your finger strength. It’s nice to be able to barely touch an electric and get a good sound but people who have never played guitar and piano have incredibly weak fingers (I don’t care if you’ve been working with your hands your whole life, it’s a different type of finger strength) and need to be trained.
Third, if you can’t produce a proper sound from a no-frills instrument, you have no business letting a piece of equipment assist you in making noise.
Chords A-G major and minor
Scales A-G major, minor and pentatonic
Pick up as many songs as you can
Learn SHEET MUSIC, not tabs. If you’re starting from scratch, and learning piano and guitar, there’s no reason to stick with tabs. They’re shitty, limited, and usually completely wrong.
Bar your index across all the guitar strings until you can play all of them with no muting, and work your way up to holding that for 3+ minutes.
And finally, the one thing I tell all my students:
Practice does NOT make perfect. Practice makes PERMANENT. If you learn something the wrong way, it will take twice as long to unlearn bad habits and relearn the right ones, so take it slow and do things right the first time.
Been playing guitar for 18 years, have played in gigs and festivals from NYC to Virginia for years, been playing piano for 22 years, competed in classical competitions from the age of 12 and played at Carnegie Hall at 17 years old. Have taught music on and off for the better part of a decade, and have also played organ for churches and funerals since I was 18.