I taught guitar for 20 years and my best students where older and had some other musical background behind them. Piano was the most common ground.
One guy was 70 and he practiced everyday for a few hours, He started having to come 2x a week just to get new lessons.
I'll recommend a few things.
First- Get an electric guitar first. You get more bang for the buck. A good acoustic might cost more and the majority of cheap acoustics have terrible set up which takes skill to fix. But where cheap electrics are easier to set up and a breeze to play.
Get a Fender style like a Tele which will chord nicer than Gibson's.
In your early stages run all four fingers up and down on each string=
Open 1-2-3-4-3-2-1-open. assign your 1st finger to the 1st fret etc.
This simple exercise will do more than anything else to get the neuro pathways flowing.
Then learn the basic open chords and the omnipotent Power chords.
Then learn the movable major scale with the root on the 6th string in G and then the 5th string in C.
Then have some fun with the Minor pentatonic ( blues/rock) scales.
The biggest challenge for keyboard players is that the guitars chords and scales patterns do not stay the same. A C chord on the piano stays the same through all octaves.
If you learn the major scale and the patterns, naming the root-1-2 etc you will figure out how the chords work faster.